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Comparing and Ordering Real Numbers

Before diving into comparing and ordering real numbers, we start with reviewing the square roots of perfect squares and estimating square roots. As you likely know, number sense is crucial for being successful in a math classroom. This unit sets the foundation for the REST of the year. As a result, I have learned to take it slow and to do formative assessments with every single skill (exit tickets are my BFF). After reading this post, you will have some lesson ideas along with teaching tips that will set your students up for success! Plus, there’s a freebie inside that you can use all year long!

Square Roots of Perfect Squares and Non-Perfect Squares

I love introducing this skill with color tiles. Start by giving students a bucket of color tiles. I like to provide them with 3 minutes to play with them before we start the activity. You can put them in partners if you are limited on color tiles!

After they finish playing, tell them to try to create a square with as few tiles as they can. This should be 1 tile. Then, ask them how many square tiles they need to make another square. This should be 4 tiles. Review how to find the area of a square.

Most will say A = l x w. Suggest they use s2 since we are working with squares. Then work your way up to at least 36 if you can. At this point, students will likely need to start sharing tiles.

Something new I added this year was an idea from my math coach and it is a KEEPER! We worked through this as we worked with the tiles.

comparing-real-numbers

Using a black pen, students could draw the radical to show the side length is the square root. This was actually kinda fun! In the future, I may have them make posters…somehow! After this, we took guided notes on perfect squares of square roots so students would have a resource to refer back to.

square-roots-of-perfect-sqaures-guided-notes

We ended by playing square roots bingo, this was our first time for the year and they’ve been asking to play more bingo!

square-roots-bingo

Estimating Square Roots

So what about non-perfect squares? We started with slides 11-20 of this free Desmos activity: Square Dance Desmos activity . It’s basically like using color tiles digitally! I had students work through it at their own pace for about 15 minutes and then we took guided notes (of course)!

estimating-square-roots

One thing I was sure to reinforce this year was using a number line. So we started with a clothesline activity to see if students could put the non-perfect squares in order. I gave each kid a card and then put them in groups of 7. Their task was to organize themselves in order!

ordering-square-roots

An idea from my math coach that I will try next year: Project a hundreds chart and have students color in the perfect squares. And then ask, β€œWhat about all of the other numbers? Do they have square roots?” I was able to try this for struggling learners after the lesson and it was super helpful! They were able to quickly see where the non-perfect squares were.

I then had students complete a scavenger hunt with a partner around the room where they had to place non-perfect and perfect squares on a number line. The number line was great because they received immediate feedback, if it spelled a word they did it correctly!

estimating-square-roots

Independently, they completed an estimating square roots drag and drop activity to reinforce the idea!

estimating-square-roots-drag-and-drop

Even though my students can use Desmos calculators (thank goodness), I noticed that they really struggled to understand that 41.2% was a percent and not a decimal in standard notation. One downside of Desmos is they attempt to type the β€œ41.2%” into the calculator and that does not work unless they type β€œ41.2% of 1” , and they quite simply don’t remember to do that! In addition, I had students looking at a number like β€œ3” and saying, β€œthere’s no decimal point…so it isn’t a decimal.” At this point, I realized I needed to do two things:

  • Change my language. instead of only saying decimal, I started saying β€œsimplified into the standard format”. I also started doing a number of the day so they could visually see the different formats for writing rational numbers.
  • Introduce them to invisible math! I had students turn to the invisible math page of their binder and pointed out that any number without a visible decimal point has an invisible one and a zero. Well, the next day, this same student came back and said, β€œDidn’t you say 0.3 is the same as 3 because of the invisible decimal point?” YIKES. Language change again…”Any number without a visible decimal point has an invisible one and a zero BEHIND IT!”

comparing-and-ordering-real-numbers

Another super tip? Use the same grid paper from square roots of perfect squares to help students them with comparing and ordering real numbers. Have them line up the decimal points.

comparing-and-ordering-real-numbers

Hey, I'm Asia!

Welcome to my Blog! I started The Sassy Math Teacher in 2020 to help teachers like you increase classroom engagement and teach with confidence! I also love to share about my life as a teacher including my favorite outfits, home items, gadgets and trips!

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3 responses.

Thank you so much for sharing this post! I am a resource teacher in a middle school, and I have used your guided notes and activities to teach and reinforce concepts, especially for my struggling 8th graders. This blog post is a really neat insight into how you use your resources in your classroom. I especially love all the different types of activities — hands-on, guided notes, and digital — as they allow students to experience the concepts in such different ways. Please keep blogging about what you are doing in your classroom, and please allow me to “steal” (purchase your resources, use ideas from your blog) ideas for my own classroom!

Hi Natasha! I am so very happy that you’ve found my blogs helpful! You are more than welcome to “steal” all of the ideas!!!

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1.1 Real Numbers: Algebra Essentials

Learning objectives.

In this section, you will:

  • Classify a real number as a natural, whole, integer, rational, or irrational number.
  • Perform calculations using order of operations.
  • Use the following properties of real numbers: commutative, associative, distributive, inverse, and identity.
  • Evaluate algebraic expressions.
  • Simplify algebraic expressions.

It is often said that mathematics is the language of science. If this is true, then an essential part of the language of mathematics is numbers. The earliest use of numbers occurred 100 centuries ago in the Middle East to count, or enumerate items. Farmers, cattle herders, and traders used tokens, stones, or markers to signify a single quantityβ€”a sheaf of grain, a head of livestock, or a fixed length of cloth, for example. Doing so made commerce possible, leading to improved communications and the spread of civilization.

Three to four thousand years ago, Egyptians introduced fractions. They first used them to show reciprocals. Later, they used them to represent the amount when a quantity was divided into equal parts.

But what if there were no cattle to trade or an entire crop of grain was lost in a flood? How could someone indicate the existence of nothing? From earliest times, people had thought of a β€œbase state” while counting and used various symbols to represent this null condition. However, it was not until about the fifth century CE in India that zero was added to the number system and used as a numeral in calculations.

Clearly, there was also a need for numbers to represent loss or debt. In India, in the seventh century CE, negative numbers were used as solutions to mathematical equations and commercial debts. The opposites of the counting numbers expanded the number system even further.

Because of the evolution of the number system, we can now perform complex calculations using these and other categories of real numbers. In this section, we will explore sets of numbers, calculations with different kinds of numbers, and the use of numbers in expressions.

Classifying a Real Number

The numbers we use for counting, or enumerating items, are the natural numbers : 1, 2, 3, 4, 5, and so on. We describe them in set notation as { 1 , 2 , 3 , ... } { 1 , 2 , 3 , ... } where the ellipsis (…) indicates that the numbers continue to infinity. The natural numbers are, of course, also called the counting numbers . Any time we enumerate the members of a team, count the coins in a collection, or tally the trees in a grove, we are using the set of natural numbers. The set of whole numbers is the set of natural numbers plus zero: { 0 , 1 , 2 , 3 , ... } . { 0 , 1 , 2 , 3 , ... } .

The set of integers adds the opposites of the natural numbers to the set of whole numbers: { ... , βˆ’3 , βˆ’2 , βˆ’1 , 0 , 1 , 2 , 3 , ... } . { ... , βˆ’3 , βˆ’2 , βˆ’1 , 0 , 1 , 2 , 3 , ... } . It is useful to note that the set of integers is made up of three distinct subsets: negative integers, zero, and positive integers. In this sense, the positive integers are just the natural numbers. Another way to think about it is that the natural numbers are a subset of the integers.

The set of rational numbers is written as { m n | m and  n are integers and  n β‰  0 } . { m n | m and  n are integers and  n β‰  0 } . Notice from the definition that rational numbers are fractions (or quotients) containing integers in both the numerator and the denominator, and the denominator is never 0. We can also see that every natural number, whole number, and integer is a rational number with a denominator of 1.

Because they are fractions, any rational number can also be expressed as a terminating or repeating decimal. Any rational number can be represented as either:

  • ⓐ a terminating decimal: 15 8 = 1.875 , 15 8 = 1.875 , or
  • β“‘ a repeating decimal: 4 11 = 0.36363636 … = 0. 36 Β― 4 11 = 0.36363636 … = 0. 36 Β―

We use a line drawn over the repeating block of numbers instead of writing the group multiple times.

Writing Integers as Rational Numbers

Write each of the following as a rational number.

Write a fraction with the integer in the numerator and 1 in the denominator.

  • ⓐ 7 = 7 1 7 = 7 1
  • β“‘ 0 = 0 1 0 = 0 1
  • β“’ βˆ’8 = βˆ’ 8 1 βˆ’8 = βˆ’ 8 1

Identifying Rational Numbers

Write each of the following rational numbers as either a terminating or repeating decimal.

  • ⓐ βˆ’ 5 7 βˆ’ 5 7
  • β“‘ 15 5 15 5
  • β“’ 13 25 13 25

Write each fraction as a decimal by dividing the numerator by the denominator.

  • ⓐ βˆ’ 5 7 = βˆ’0. 714285 β€”β€”β€” , βˆ’ 5 7 = βˆ’0. 714285 β€”β€”β€” , a repeating decimal
  • β“‘ 15 5 = 3 15 5 = 3 (or 3.0), a terminating decimal
  • β“’ 13 25 = 0.52 , 13 25 = 0.52 , a terminating decimal
  • ⓐ 68 17 68 17
  • β“‘ 8 13 8 13
  • β“’ βˆ’ 17 20 βˆ’ 17 20

Irrational Numbers

At some point in the ancient past, someone discovered that not all numbers are rational numbers. A builder, for instance, may have found that the diagonal of a square with unit sides was not 2 or even 3 2 , 3 2 , but was something else. Or a garment maker might have observed that the ratio of the circumference to the diameter of a roll of cloth was a little bit more than 3, but still not a rational number. Such numbers are said to be irrational because they cannot be written as fractions. These numbers make up the set of irrational numbers . Irrational numbers cannot be expressed as a fraction of two integers. It is impossible to describe this set of numbers by a single rule except to say that a number is irrational if it is not rational. So we write this as shown.

Differentiating Rational and Irrational Numbers

Determine whether each of the following numbers is rational or irrational. If it is rational, determine whether it is a terminating or repeating decimal.

  • β“‘ 33 9 33 9
  • β““ 17 34 17 34
  • β“” 0.3033033303333 … 0.3033033303333 …
  • ⓐ 25 : 25 : This can be simplified as 25 = 5. 25 = 5. Therefore, 25 25 is rational.

So, 33 9 33 9 is rational and a repeating decimal.

  • β“’ 11 : 11 11 : 11 is irrational because 11 is not a perfect square and 11 11 cannot be expressed as a fraction.

So, 17 34 17 34 is rational and a terminating decimal.

  • β“” 0.3033033303333 … 0.3033033303333 … is not a terminating decimal. Also note that there is no repeating pattern because the group of 3s increases each time. Therefore it is neither a terminating nor a repeating decimal and, hence, not a rational number. It is an irrational number.
  • ⓐ 7 77 7 77
  • β“’ 4.27027002700027 … 4.27027002700027 …
  • β““ 91 13 91 13

Real Numbers

Given any number n , we know that n is either rational or irrational. It cannot be both. The sets of rational and irrational numbers together make up the set of real numbers . As we saw with integers, the real numbers can be divided into three subsets: negative real numbers, zero, and positive real numbers. Each subset includes fractions, decimals, and irrational numbers according to their algebraic sign (+ or –). Zero is considered neither positive nor negative.

The real numbers can be visualized on a horizontal number line with an arbitrary point chosen as 0, with negative numbers to the left of 0 and positive numbers to the right of 0. A fixed unit distance is then used to mark off each integer (or other basic value) on either side of 0. Any real number corresponds to a unique position on the number line.The converse is also true: Each location on the number line corresponds to exactly one real number. This is known as a one-to-one correspondence. We refer to this as the real number line as shown in Figure 1 .

Classifying Real Numbers

Classify each number as either positive or negative and as either rational or irrational. Does the number lie to the left or the right of 0 on the number line?

  • ⓐ βˆ’ 10 3 βˆ’ 10 3
  • β“’ βˆ’ 289 βˆ’ 289
  • β““ βˆ’6 Ο€ βˆ’6 Ο€
  • β“” 0.615384615384 … 0.615384615384 …
  • ⓐ βˆ’ 10 3 βˆ’ 10 3 is negative and rational. It lies to the left of 0 on the number line.
  • β“‘ 5 5 is positive and irrational. It lies to the right of 0.
  • β“’ βˆ’ 289 = βˆ’ 17 2 = βˆ’17 βˆ’ 289 = βˆ’ 17 2 = βˆ’17 is negative and rational. It lies to the left of 0.
  • β““ βˆ’6 Ο€ βˆ’6 Ο€ is negative and irrational. It lies to the left of 0.
  • β“” 0.615384615384 … 0.615384615384 … is a repeating decimal so it is rational and positive. It lies to the right of 0.
  • β“‘ βˆ’11.411411411 … βˆ’11.411411411 …
  • β“’ 47 19 47 19
  • β““ βˆ’ 5 2 βˆ’ 5 2
  • β“” 6.210735 6.210735

Sets of Numbers as Subsets

Beginning with the natural numbers, we have expanded each set to form a larger set, meaning that there is a subset relationship between the sets of numbers we have encountered so far. These relationships become more obvious when seen as a diagram, such as Figure 2 .

Sets of Numbers

The set of natural numbers includes the numbers used for counting: { 1 , 2 , 3 , ... } . { 1 , 2 , 3 , ... } .

The set of whole numbers is the set of natural numbers plus zero: { 0 , 1 , 2 , 3 , ... } . { 0 , 1 , 2 , 3 , ... } .

The set of integers adds the negative natural numbers to the set of whole numbers: { ... , βˆ’3 , βˆ’2 , βˆ’1 , 0 , 1 , 2 , 3 , ... } . { ... , βˆ’3 , βˆ’2 , βˆ’1 , 0 , 1 , 2 , 3 , ... } .

The set of rational numbers includes fractions written as { m n | m and  n are integers and  n β‰  0 } . { m n | m and  n are integers and  n β‰  0 } .

The set of irrational numbers is the set of numbers that are not rational, are nonrepeating, and are nonterminating: { h | h is not a rational number } . { h | h is not a rational number } .

Differentiating the Sets of Numbers

Classify each number as being a natural number ( N ), whole number ( W ), integer ( I ), rational number ( Q ), and/or irrational number ( Qβ€² ).

  • β“” 3.2121121112 … 3.2121121112 …
  • ⓐ βˆ’ 35 7 βˆ’ 35 7
  • β“” 4.763763763 … 4.763763763 …

Performing Calculations Using the Order of Operations

When we multiply a number by itself, we square it or raise it to a power of 2. For example, 4 2 = 4 β‹… 4 = 16. 4 2 = 4 β‹… 4 = 16. We can raise any number to any power. In general, the exponential notation a n a n means that the number or variable a a is used as a factor n n times.

In this notation, a n a n is read as the n th power of a , a , or a a to the n n where a a is called the base and n n is called the exponent . A term in exponential notation may be part of a mathematical expression, which is a combination of numbers and operations. For example, 24 + 6 β‹… 2 3 βˆ’ 4 2 24 + 6 β‹… 2 3 βˆ’ 4 2 is a mathematical expression.

To evaluate a mathematical expression, we perform the various operations. However, we do not perform them in any random order. We use the order of operations . This is a sequence of rules for evaluating such expressions.

Recall that in mathematics we use parentheses ( ), brackets [ ], and braces { } to group numbers and expressions so that anything appearing within the symbols is treated as a unit. Additionally, fraction bars, radicals, and absolute value bars are treated as grouping symbols. When evaluating a mathematical expression, begin by simplifying expressions within grouping symbols.

The next step is to address any exponents or radicals. Afterward, perform multiplication and division from left to right and finally addition and subtraction from left to right.

Let’s take a look at the expression provided.

There are no grouping symbols, so we move on to exponents or radicals. The number 4 is raised to a power of 2, so simplify 4 2 4 2 as 16.

Next, perform multiplication or division, left to right.

Lastly, perform addition or subtraction, left to right.

Therefore, 24 + 6 β‹… 2 3 βˆ’ 4 2 = 12. 24 + 6 β‹… 2 3 βˆ’ 4 2 = 12.

For some complicated expressions, several passes through the order of operations will be needed. For instance, there may be a radical expression inside parentheses that must be simplified before the parentheses are evaluated. Following the order of operations ensures that anyone simplifying the same mathematical expression will get the same result.

Order of Operations

Operations in mathematical expressions must be evaluated in a systematic order, which can be simplified using the acronym PEMDAS :

P (arentheses) E (xponents) M (ultiplication) and D (ivision) A (ddition) and S (ubtraction)

Given a mathematical expression, simplify it using the order of operations.

  • Step 1. Simplify any expressions within grouping symbols.
  • Step 2. Simplify any expressions containing exponents or radicals.
  • Step 3. Perform any multiplication and division in order, from left to right.
  • Step 4. Perform any addition and subtraction in order, from left to right.

Using the Order of Operations

Use the order of operations to evaluate each of the following expressions.

  • ⓐ ( 3 β‹… 2 ) 2 βˆ’ 4 ( 6 + 2 ) ( 3 β‹… 2 ) 2 βˆ’ 4 ( 6 + 2 )
  • β“‘ 5 2 βˆ’ 4 7 βˆ’ 11 βˆ’ 2 5 2 βˆ’ 4 7 βˆ’ 11 βˆ’ 2
  • β“’ 6 βˆ’ | 5 βˆ’ 8 | + 3 ( 4 βˆ’ 1 ) 6 βˆ’ | 5 βˆ’ 8 | + 3 ( 4 βˆ’ 1 )
  • β““ 14 βˆ’ 3 β‹… 2 2 β‹… 5 βˆ’ 3 2 14 βˆ’ 3 β‹… 2 2 β‹… 5 βˆ’ 3 2
  • β“” 7 ( 5 β‹… 3 ) βˆ’ 2 [ ( 6 βˆ’ 3 ) βˆ’ 4 2 ] + 1 7 ( 5 β‹… 3 ) βˆ’ 2 [ ( 6 βˆ’ 3 ) βˆ’ 4 2 ] + 1
  • ⓐ ( 3 β‹… 2 ) 2 βˆ’ 4 ( 6 + 2 ) = ( 6 ) 2 βˆ’ 4 ( 8 ) Simplify parentheses. = 36 βˆ’ 4 ( 8 ) Simplify exponent. = 36 βˆ’ 32 Simplify multiplication. = 4 Simplify subtraction. ( 3 β‹… 2 ) 2 βˆ’ 4 ( 6 + 2 ) = ( 6 ) 2 βˆ’ 4 ( 8 ) Simplify parentheses. = 36 βˆ’ 4 ( 8 ) Simplify exponent. = 36 βˆ’ 32 Simplify multiplication. = 4 Simplify subtraction.

Note that in the first step, the radical is treated as a grouping symbol, like parentheses. Also, in the third step, the fraction bar is considered a grouping symbol so the numerator is considered to be grouped.

  • β“’ 6 βˆ’ | 5 βˆ’ 8 | + 3 | 4 βˆ’ 1 | = 6 βˆ’ | βˆ’3 | + 3 ( 3 ) Simplify inside grouping symbols. = 6 - ( 3 ) + 3 ( 3 ) Simplify absolute value. = 6 - 3 + 9 Simplify multiplication. = 12 Simplify addition. 6 βˆ’ | 5 βˆ’ 8 | + 3 | 4 βˆ’ 1 | = 6 βˆ’ | βˆ’3 | + 3 ( 3 ) Simplify inside grouping symbols. = 6 - ( 3 ) + 3 ( 3 ) Simplify absolute value. = 6 - 3 + 9 Simplify multiplication. = 12 Simplify addition.

In this example, the fraction bar separates the numerator and denominator, which we simplify separately until the last step.

  • β“” 7 ( 5 β‹… 3 ) βˆ’ 2 [ ( 6 βˆ’ 3 ) βˆ’ 4 2 ] + 1 = 7 ( 15 ) βˆ’ 2 [ ( 3 ) βˆ’ 4 2 ] + 1 Simplify inside parentheses. = 7 ( 15 ) βˆ’ 2 ( 3 βˆ’ 16 ) + 1 Simplify exponent. = 7 ( 15 ) βˆ’ 2 ( βˆ’13 ) + 1 Subtract. = 105 + 26 + 1 Multiply. = 132 Add. 7 ( 5 β‹… 3 ) βˆ’ 2 [ ( 6 βˆ’ 3 ) βˆ’ 4 2 ] + 1 = 7 ( 15 ) βˆ’ 2 [ ( 3 ) βˆ’ 4 2 ] + 1 Simplify inside parentheses. = 7 ( 15 ) βˆ’ 2 ( 3 βˆ’ 16 ) + 1 Simplify exponent. = 7 ( 15 ) βˆ’ 2 ( βˆ’13 ) + 1 Subtract. = 105 + 26 + 1 Multiply. = 132 Add.
  • ⓐ 5 2 βˆ’ 4 2 + 7 ( 5 βˆ’ 4 ) 2 5 2 βˆ’ 4 2 + 7 ( 5 βˆ’ 4 ) 2
  • β“‘ 1 + 7 β‹… 5 βˆ’ 8 β‹… 4 9 βˆ’ 6 1 + 7 β‹… 5 βˆ’ 8 β‹… 4 9 βˆ’ 6
  • β“’ | 1.8 βˆ’ 4.3 | + 0.4 15 + 10 | 1.8 βˆ’ 4.3 | + 0.4 15 + 10
  • β““ 1 2 [ 5 β‹… 3 2 βˆ’ 7 2 ] + 1 3 β‹… 9 2 1 2 [ 5 β‹… 3 2 βˆ’ 7 2 ] + 1 3 β‹… 9 2
  • β“” [ ( 3 βˆ’ 8 ) 2 βˆ’ 4 ] βˆ’ ( 3 βˆ’ 8 ) [ ( 3 βˆ’ 8 ) 2 βˆ’ 4 ] βˆ’ ( 3 βˆ’ 8 )

Using Properties of Real Numbers

For some activities we perform, the order of certain operations does not matter, but the order of other operations does. For example, it does not make a difference if we put on the right shoe before the left or vice-versa. However, it does matter whether we put on shoes or socks first. The same thing is true for operations in mathematics.

Commutative Properties

The commutative property of addition states that numbers may be added in any order without affecting the sum.

We can better see this relationship when using real numbers.

Similarly, the commutative property of multiplication states that numbers may be multiplied in any order without affecting the product.

Again, consider an example with real numbers.

It is important to note that neither subtraction nor division is commutative. For example, 17 βˆ’ 5 17 βˆ’ 5 is not the same as 5 βˆ’ 17. 5 βˆ’ 17. Similarly, 20 Γ· 5 β‰  5 Γ· 20. 20 Γ· 5 β‰  5 Γ· 20.

Associative Properties

The associative property of multiplication tells us that it does not matter how we group numbers when multiplying. We can move the grouping symbols to make the calculation easier, and the product remains the same.

Consider this example.

The associative property of addition tells us that numbers may be grouped differently without affecting the sum.

This property can be especially helpful when dealing with negative integers. Consider this example.

Are subtraction and division associative? Review these examples.

As we can see, neither subtraction nor division is associative.

Distributive Property

The distributive property states that the product of a factor times a sum is the sum of the factor times each term in the sum.

This property combines both addition and multiplication (and is the only property to do so). Let us consider an example.

Note that 4 is outside the grouping symbols, so we distribute the 4 by multiplying it by 12, multiplying it by –7, and adding the products.

To be more precise when describing this property, we say that multiplication distributes over addition. The reverse is not true, as we can see in this example.

A special case of the distributive property occurs when a sum of terms is subtracted.

For example, consider the difference 12 βˆ’ ( 5 + 3 ) . 12 βˆ’ ( 5 + 3 ) . We can rewrite the difference of the two terms 12 and ( 5 + 3 ) ( 5 + 3 ) by turning the subtraction expression into addition of the opposite. So instead of subtracting ( 5 + 3 ) , ( 5 + 3 ) , we add the opposite.

Now, distribute βˆ’1 βˆ’1 and simplify the result.

This seems like a lot of trouble for a simple sum, but it illustrates a powerful result that will be useful once we introduce algebraic terms. To subtract a sum of terms, change the sign of each term and add the results. With this in mind, we can rewrite the last example.

Identity Properties

The identity property of addition states that there is a unique number, called the additive identity (0) that, when added to a number, results in the original number.

The identity property of multiplication states that there is a unique number, called the multiplicative identity (1) that, when multiplied by a number, results in the original number.

For example, we have ( βˆ’6 ) + 0 = βˆ’6 ( βˆ’6 ) + 0 = βˆ’6 and 23 β‹… 1 = 23. 23 β‹… 1 = 23. There are no exceptions for these properties; they work for every real number, including 0 and 1.

Inverse Properties

The inverse property of addition states that, for every real number a , there is a unique number, called the additive inverse (or opposite), denoted by (βˆ’ a ), that, when added to the original number, results in the additive identity, 0.

For example, if a = βˆ’8 , a = βˆ’8 , the additive inverse is 8, since ( βˆ’8 ) + 8 = 0. ( βˆ’8 ) + 8 = 0.

The inverse property of multiplication holds for all real numbers except 0 because the reciprocal of 0 is not defined. The property states that, for every real number a , there is a unique number, called the multiplicative inverse (or reciprocal), denoted 1 a , 1 a , that, when multiplied by the original number, results in the multiplicative identity, 1.

For example, if a = βˆ’ 2 3 , a = βˆ’ 2 3 , the reciprocal, denoted 1 a , 1 a , is βˆ’ 3 2 βˆ’ 3 2 because

Properties of Real Numbers

The following properties hold for real numbers a , b , and c .

Use the properties of real numbers to rewrite and simplify each expression. State which properties apply.

  • ⓐ 3 β‹… 6 + 3 β‹… 4 3 β‹… 6 + 3 β‹… 4
  • β“‘ ( 5 + 8 ) + ( βˆ’8 ) ( 5 + 8 ) + ( βˆ’8 )
  • β“’ 6 βˆ’ ( 15 + 9 ) 6 βˆ’ ( 15 + 9 )
  • β““ 4 7 β‹… ( 2 3 β‹… 7 4 ) 4 7 β‹… ( 2 3 β‹… 7 4 )
  • β“” 100 β‹… [ 0.75 + ( βˆ’2.38 ) ] 100 β‹… [ 0.75 + ( βˆ’2.38 ) ]
  • ⓐ 3 β‹… 6 + 3 β‹… 4 = 3 β‹… ( 6 + 4 ) Distributive property. = 3 β‹… 10 Simplify. = 30 Simplify. 3 β‹… 6 + 3 β‹… 4 = 3 β‹… ( 6 + 4 ) Distributive property. = 3 β‹… 10 Simplify. = 30 Simplify.
  • β“‘ ( 5 + 8 ) + ( βˆ’8 ) = 5 + [ 8 + ( βˆ’8 ) ] Associative property of addition. = 5 + 0 Inverse property of addition. = 5 Identity property of addition. ( 5 + 8 ) + ( βˆ’8 ) = 5 + [ 8 + ( βˆ’8 ) ] Associative property of addition. = 5 + 0 Inverse property of addition. = 5 Identity property of addition.
  • β“’ 6 βˆ’ ( 15 + 9 ) = 6 + [ ( βˆ’15 ) + ( βˆ’9 ) ] Distributive property. = 6 + ( βˆ’24 ) Simplify. = βˆ’18 Simplify. 6 βˆ’ ( 15 + 9 ) = 6 + [ ( βˆ’15 ) + ( βˆ’9 ) ] Distributive property. = 6 + ( βˆ’24 ) Simplify. = βˆ’18 Simplify.
  • β““ 4 7 β‹… ( 2 3 β‹… 7 4 ) = 4 7 β‹… ( 7 4 β‹… 2 3 ) Commutative property of multiplication. = ( 4 7 β‹… 7 4 ) β‹… 2 3 Associative property of multiplication. = 1 β‹… 2 3 Inverse property of multiplication. = 2 3 Identity property of multiplication. 4 7 β‹… ( 2 3 β‹… 7 4 ) = 4 7 β‹… ( 7 4 β‹… 2 3 ) Commutative property of multiplication. = ( 4 7 β‹… 7 4 ) β‹… 2 3 Associative property of multiplication. = 1 β‹… 2 3 Inverse property of multiplication. = 2 3 Identity property of multiplication.
  • β“” 100 β‹… [ 0.75 + ( βˆ’ 2.38 ) ] = 100 β‹… 0.75 + 100 β‹… ( βˆ’2.38 ) Distributive property. = 75 + ( βˆ’238 ) Simplify. = βˆ’163 Simplify. 100 β‹… [ 0.75 + ( βˆ’ 2.38 ) ] = 100 β‹… 0.75 + 100 β‹… ( βˆ’2.38 ) Distributive property. = 75 + ( βˆ’238 ) Simplify. = βˆ’163 Simplify.
  • ⓐ ( βˆ’ 23 5 ) β‹… [ 11 β‹… ( βˆ’ 5 23 ) ] ( βˆ’ 23 5 ) β‹… [ 11 β‹… ( βˆ’ 5 23 ) ]
  • β“‘ 5 β‹… ( 6.2 + 0.4 ) 5 β‹… ( 6.2 + 0.4 )
  • β“’ 18 βˆ’ ( 7 βˆ’15 ) 18 βˆ’ ( 7 βˆ’15 )
  • β““ 17 18 + [ 4 9 + ( βˆ’ 17 18 ) ] 17 18 + [ 4 9 + ( βˆ’ 17 18 ) ]
  • β“” 6 β‹… ( βˆ’3 ) + 6 β‹… 3 6 β‹… ( βˆ’3 ) + 6 β‹… 3

Evaluating Algebraic Expressions

So far, the mathematical expressions we have seen have involved real numbers only. In mathematics, we may see expressions such as x + 5 , 4 3 Ο€ r 3 , x + 5 , 4 3 Ο€ r 3 , or 2 m 3 n 2 . 2 m 3 n 2 . In the expression x + 5 , x + 5 , 5 is called a constant because it does not vary and x is called a variable because it does. (In naming the variable, ignore any exponents or radicals containing the variable.) An algebraic expression is a collection of constants and variables joined together by the algebraic operations of addition, subtraction, multiplication, and division.

We have already seen some real number examples of exponential notation, a shorthand method of writing products of the same factor. When variables are used, the constants and variables are treated the same way.

In each case, the exponent tells us how many factors of the base to use, whether the base consists of constants or variables.

Any variable in an algebraic expression may take on or be assigned different values. When that happens, the value of the algebraic expression changes. To evaluate an algebraic expression means to determine the value of the expression for a given value of each variable in the expression. Replace each variable in the expression with the given value, then simplify the resulting expression using the order of operations. If the algebraic expression contains more than one variable, replace each variable with its assigned value and simplify the expression as before.

Describing Algebraic Expressions

List the constants and variables for each algebraic expression.

  • β“‘ 4 3 Ο€ r 3 4 3 Ο€ r 3
  • β“’ 2 m 3 n 2 2 m 3 n 2
  • ⓐ 2 Ο€ r ( r + h ) 2 Ο€ r ( r + h )
  • β“‘ 2( L + W )
  • β“’ 4 y 3 + y 4 y 3 + y

Evaluating an Algebraic Expression at Different Values

Evaluate the expression 2 x βˆ’ 7 2 x βˆ’ 7 for each value for x.

  • ⓐ x = 0 x = 0
  • β“‘ x = 1 x = 1
  • β“’ x = 1 2 x = 1 2
  • β““ x = βˆ’4 x = βˆ’4
  • ⓐ Substitute 0 for x . x . 2 x βˆ’ 7 = 2 ( 0 ) βˆ’ 7 = 0 βˆ’ 7 = βˆ’7 2 x βˆ’ 7 = 2 ( 0 ) βˆ’ 7 = 0 βˆ’ 7 = βˆ’7
  • β“‘ Substitute 1 for x . x . 2 x βˆ’ 7 = 2 ( 1 ) βˆ’ 7 = 2 βˆ’ 7 = βˆ’5 2 x βˆ’ 7 = 2 ( 1 ) βˆ’ 7 = 2 βˆ’ 7 = βˆ’5
  • β“’ Substitute 1 2 1 2 for x . x . 2 x βˆ’ 7 = 2 ( 1 2 ) βˆ’ 7 = 1 βˆ’ 7 = βˆ’6 2 x βˆ’ 7 = 2 ( 1 2 ) βˆ’ 7 = 1 βˆ’ 7 = βˆ’6
  • β““ Substitute βˆ’4 βˆ’4 for x . x . 2 x βˆ’ 7 = 2 ( βˆ’ 4 ) βˆ’ 7 = βˆ’ 8 βˆ’ 7 = βˆ’15 2 x βˆ’ 7 = 2 ( βˆ’ 4 ) βˆ’ 7 = βˆ’ 8 βˆ’ 7 = βˆ’15

Evaluate the expression 11 βˆ’ 3 y 11 βˆ’ 3 y for each value for y.

  • ⓐ y = 2 y = 2
  • β“‘ y = 0 y = 0
  • β“’ y = 2 3 y = 2 3
  • β““ y = βˆ’5 y = βˆ’5

Evaluate each expression for the given values.

  • ⓐ x + 5 x + 5 for x = βˆ’5 x = βˆ’5
  • β“‘ t 2 t βˆ’1 t 2 t βˆ’1 for t = 10 t = 10
  • β“’ 4 3 Ο€ r 3 4 3 Ο€ r 3 for r = 5 r = 5
  • β““ a + a b + b a + a b + b for a = 11 , b = βˆ’8 a = 11 , b = βˆ’8
  • β“” 2 m 3 n 2 2 m 3 n 2 for m = 2 , n = 3 m = 2 , n = 3
  • ⓐ Substitute βˆ’5 βˆ’5 for x . x . x + 5 = ( βˆ’5 ) + 5 = 0 x + 5 = ( βˆ’5 ) + 5 = 0
  • β“‘ Substitute 10 for t . t . t 2 t βˆ’ 1 = ( 10 ) 2 ( 10 ) βˆ’ 1 = 10 20 βˆ’ 1 = 10 19 t 2 t βˆ’ 1 = ( 10 ) 2 ( 10 ) βˆ’ 1 = 10 20 βˆ’ 1 = 10 19
  • β“’ Substitute 5 for r . r . 4 3 Ο€ r 3 = 4 3 Ο€ ( 5 ) 3 = 4 3 Ο€ ( 125 ) = 500 3 Ο€ 4 3 Ο€ r 3 = 4 3 Ο€ ( 5 ) 3 = 4 3 Ο€ ( 125 ) = 500 3 Ο€
  • β““ Substitute 11 for a a and –8 for b . b . a + a b + b = ( 11 ) + ( 11 ) ( βˆ’8 ) + ( βˆ’8 ) = 11 βˆ’ 88 βˆ’ 8 = βˆ’85 a + a b + b = ( 11 ) + ( 11 ) ( βˆ’8 ) + ( βˆ’8 ) = 11 βˆ’ 88 βˆ’ 8 = βˆ’85
  • β“” Substitute 2 for m m and 3 for n . n . 2 m 3 n 2 = 2 ( 2 ) 3 ( 3 ) 2 = 2 ( 8 ) ( 9 ) = 144 = 12 2 m 3 n 2 = 2 ( 2 ) 3 ( 3 ) 2 = 2 ( 8 ) ( 9 ) = 144 = 12
  • ⓐ y + 3 y βˆ’ 3 y + 3 y βˆ’ 3 for y = 5 y = 5
  • β“‘ 7 βˆ’ 2 t 7 βˆ’ 2 t for t = βˆ’2 t = βˆ’2
  • β“’ 1 3 Ο€ r 2 1 3 Ο€ r 2 for r = 11 r = 11
  • β““ ( p 2 q ) 3 ( p 2 q ) 3 for p = βˆ’2 , q = 3 p = βˆ’2 , q = 3
  • β“” 4 ( m βˆ’ n ) βˆ’ 5 ( n βˆ’ m ) 4 ( m βˆ’ n ) βˆ’ 5 ( n βˆ’ m ) for m = 2 3 , n = 1 3 m = 2 3 , n = 1 3

An equation is a mathematical statement indicating that two expressions are equal. The expressions can be numerical or algebraic. The equation is not inherently true or false, but only a proposition. The values that make the equation true, the solutions, are found using the properties of real numbers and other results. For example, the equation 2 x + 1 = 7 2 x + 1 = 7 has the solution of 3 because when we substitute 3 for x x in the equation, we obtain the true statement 2 ( 3 ) + 1 = 7. 2 ( 3 ) + 1 = 7.

A formula is an equation expressing a relationship between constant and variable quantities. Very often, the equation is a means of finding the value of one quantity (often a single variable) in terms of another or other quantities. One of the most common examples is the formula for finding the area A A of a circle in terms of the radius r r of the circle: A = Ο€ r 2 . A = Ο€ r 2 . For any value of r , r , the area A A can be found by evaluating the expression Ο€ r 2 . Ο€ r 2 .

Using a Formula

A right circular cylinder with radius r r and height h h has the surface area S S (in square units) given by the formula S = 2 Ο€ r ( r + h ) . S = 2 Ο€ r ( r + h ) . See Figure 3 . Find the surface area of a cylinder with radius 6 in. and height 9 in. Leave the answer in terms of Ο€ . Ο€ .

Evaluate the expression 2 Ο€ r ( r + h ) 2 Ο€ r ( r + h ) for r = 6 r = 6 and h = 9. h = 9.

The surface area is 180 Ο€ 180 Ο€ square inches.

A photograph with length L and width W is placed in a mat of width 8 centimeters (cm). The area of the mat (in square centimeters, or cm 2 ) is found to be A = ( L + 16 ) ( W + 16 ) βˆ’ L β‹… W . A = ( L + 16 ) ( W + 16 ) βˆ’ L β‹… W . See Figure 4 . Find the area of a mat for a photograph with length 32 cm and width 24 cm.

Simplifying Algebraic Expressions

Sometimes we can simplify an algebraic expression to make it easier to evaluate or to use in some other way. To do so, we use the properties of real numbers. We can use the same properties in formulas because they contain algebraic expressions.

Simplify each algebraic expression.

  • ⓐ 3 x βˆ’ 2 y + x βˆ’ 3 y βˆ’ 7 3 x βˆ’ 2 y + x βˆ’ 3 y βˆ’ 7
  • β“‘ 2 r βˆ’ 5 ( 3 βˆ’ r ) + 4 2 r βˆ’ 5 ( 3 βˆ’ r ) + 4
  • β“’ ( 4 t βˆ’ 5 4 s ) βˆ’ ( 2 3 t + 2 s ) ( 4 t βˆ’ 5 4 s ) βˆ’ ( 2 3 t + 2 s )
  • β““ 2 m n βˆ’ 5 m + 3 m n + n 2 m n βˆ’ 5 m + 3 m n + n
  • ⓐ 3 x βˆ’ 2 y + x βˆ’ 3 y βˆ’ 7 = 3 x + x βˆ’ 2 y βˆ’ 3 y βˆ’ 7 Commutative property of addition. = 4 x βˆ’ 5 y βˆ’ 7 Simplify. 3 x βˆ’ 2 y + x βˆ’ 3 y βˆ’ 7 = 3 x + x βˆ’ 2 y βˆ’ 3 y βˆ’ 7 Commutative property of addition. = 4 x βˆ’ 5 y βˆ’ 7 Simplify.
  • β“‘ 2 r βˆ’ 5 ( 3 βˆ’ r ) + 4 = 2 r βˆ’ 15 + 5 r + 4 Distributive property. = 2 r + 5 r βˆ’ 15 + 4 Commutative property of addition. = 7 r βˆ’ 11 Simplify. 2 r βˆ’ 5 ( 3 βˆ’ r ) + 4 = 2 r βˆ’ 15 + 5 r + 4 Distributive property. = 2 r + 5 r βˆ’ 15 + 4 Commutative property of addition. = 7 r βˆ’ 11 Simplify.
  • β“’ ( 4 t βˆ’ 5 4 s ) βˆ’ ( 2 3 t + 2 s ) = 4 t βˆ’ 5 4 s βˆ’ 2 3 t βˆ’ 2 s Distributive property. = 4 t βˆ’ 2 3 t βˆ’ 5 4 s βˆ’ 2 s Commutative property of addition. = 10 3 t βˆ’ 13 4 s Simplify. ( 4 t βˆ’ 5 4 s ) βˆ’ ( 2 3 t + 2 s ) = 4 t βˆ’ 5 4 s βˆ’ 2 3 t βˆ’ 2 s Distributive property. = 4 t βˆ’ 2 3 t βˆ’ 5 4 s βˆ’ 2 s Commutative property of addition. = 10 3 t βˆ’ 13 4 s Simplify.
  • β““ 2 m n βˆ’ 5 m + 3 m n + n = 2 m n + 3 m n βˆ’ 5 m + n Commutative property of addition. = 5 m n βˆ’ 5 m + n Simplify. 2 m n βˆ’ 5 m + 3 m n + n = 2 m n + 3 m n βˆ’ 5 m + n Commutative property of addition. = 5 m n βˆ’ 5 m + n Simplify.
  • ⓐ 2 3 y βˆ’ 2 ( 4 3 y + z ) 2 3 y βˆ’ 2 ( 4 3 y + z )
  • β“‘ 5 t βˆ’ 2 βˆ’ 3 t + 1 5 t βˆ’ 2 βˆ’ 3 t + 1
  • β“’ 4 p ( q βˆ’ 1 ) + q ( 1 βˆ’ p ) 4 p ( q βˆ’ 1 ) + q ( 1 βˆ’ p )
  • β““ 9 r βˆ’ ( s + 2 r ) + ( 6 βˆ’ s ) 9 r βˆ’ ( s + 2 r ) + ( 6 βˆ’ s )

Simplifying a Formula

A rectangle with length L L and width W W has a perimeter P P given by P = L + W + L + W . P = L + W + L + W . Simplify this expression.

If the amount P P is deposited into an account paying simple interest r r for time t , t , the total value of the deposit A A is given by A = P + P r t . A = P + P r t . Simplify the expression. (This formula will be explored in more detail later in the course.)

Access these online resources for additional instruction and practice with real numbers.

  • Simplify an Expression.
  • Evaluate an Expression 1.
  • Evaluate an Expression 2.

1.1 Section Exercises

Is 2 2 an example of a rational terminating, rational repeating, or irrational number? Tell why it fits that category.

What is the order of operations? What acronym is used to describe the order of operations, and what does it stand for?

What do the Associative Properties allow us to do when following the order of operations? Explain your answer.

For the following exercises, simplify the given expression.

10 + 2 Γ— ( 5 βˆ’ 3 ) 10 + 2 Γ— ( 5 βˆ’ 3 )

6 Γ· 2 βˆ’ ( 81 Γ· 3 2 ) 6 Γ· 2 βˆ’ ( 81 Γ· 3 2 )

18 + ( 6 βˆ’ 8 ) 3 18 + ( 6 βˆ’ 8 ) 3

βˆ’2 Γ— [ 16 Γ· ( 8 βˆ’ 4 ) 2 ] 2 βˆ’2 Γ— [ 16 Γ· ( 8 βˆ’ 4 ) 2 ] 2

4 βˆ’ 6 + 2 Γ— 7 4 βˆ’ 6 + 2 Γ— 7

3 ( 5 βˆ’ 8 ) 3 ( 5 βˆ’ 8 )

4 + 6 βˆ’ 10 Γ· 2 4 + 6 βˆ’ 10 Γ· 2

12 Γ· ( 36 Γ· 9 ) + 6 12 Γ· ( 36 Γ· 9 ) + 6

( 4 + 5 ) 2 Γ· 3 ( 4 + 5 ) 2 Γ· 3

3 βˆ’ 12 Γ— 2 + 19 3 βˆ’ 12 Γ— 2 + 19

2 + 8 Γ— 7 Γ· 4 2 + 8 Γ— 7 Γ· 4

5 + ( 6 + 4 ) βˆ’ 11 5 + ( 6 + 4 ) βˆ’ 11

9 βˆ’ 18 Γ· 3 2 9 βˆ’ 18 Γ· 3 2

14 Γ— 3 Γ· 7 βˆ’ 6 14 Γ— 3 Γ· 7 βˆ’ 6

9 βˆ’ ( 3 + 11 ) Γ— 2 9 βˆ’ ( 3 + 11 ) Γ— 2

6 + 2 Γ— 2 βˆ’ 1 6 + 2 Γ— 2 βˆ’ 1

64 Γ· ( 8 + 4 Γ— 2 ) 64 Γ· ( 8 + 4 Γ— 2 )

9 + 4 ( 2 2 ) 9 + 4 ( 2 2 )

( 12 Γ· 3 Γ— 3 ) 2 ( 12 Γ· 3 Γ— 3 ) 2

25 Γ· 5 2 βˆ’ 7 25 Γ· 5 2 βˆ’ 7

( 15 βˆ’ 7 ) Γ— ( 3 βˆ’ 7 ) ( 15 βˆ’ 7 ) Γ— ( 3 βˆ’ 7 )

2 Γ— 4 βˆ’ 9 ( βˆ’1 ) 2 Γ— 4 βˆ’ 9 ( βˆ’1 )

4 2 βˆ’ 25 Γ— 1 5 4 2 βˆ’ 25 Γ— 1 5

12 ( 3 βˆ’ 1 ) Γ· 6 12 ( 3 βˆ’ 1 ) Γ· 6

For the following exercises, evaluate the expression using the given value of the variable.

8 ( x + 3 ) – 64 8 ( x + 3 ) – 64 for x = 2 x = 2

4 y + 8 – 2 y 4 y + 8 – 2 y for y = 3 y = 3

( 11 a + 3 ) βˆ’ 18 a + 4 ( 11 a + 3 ) βˆ’ 18 a + 4 for a = –2 a = –2

4 z βˆ’ 2 z ( 1 + 4 ) – 36 4 z βˆ’ 2 z ( 1 + 4 ) – 36 for z = 5 z = 5

4 y ( 7 βˆ’ 2 ) 2 + 200 4 y ( 7 βˆ’ 2 ) 2 + 200 for y = –2 y = –2

βˆ’ ( 2 x ) 2 + 1 + 3 βˆ’ ( 2 x ) 2 + 1 + 3 for x = 2 x = 2

For the 8 ( 2 + 4 ) βˆ’ 15 b + b 8 ( 2 + 4 ) βˆ’ 15 b + b for b = –3 b = –3

2 ( 11 c βˆ’ 4 ) – 36 2 ( 11 c βˆ’ 4 ) – 36 for c = 0 c = 0

4 ( 3 βˆ’ 1 ) x – 4 4 ( 3 βˆ’ 1 ) x – 4 for x = 10 x = 10

1 4 ( 8 w βˆ’ 4 2 ) 1 4 ( 8 w βˆ’ 4 2 ) for w = 1 w = 1

For the following exercises, simplify the expression.

4 x + x ( 13 βˆ’ 7 ) 4 x + x ( 13 βˆ’ 7 )

2 y βˆ’ ( 4 ) 2 y βˆ’ 11 2 y βˆ’ ( 4 ) 2 y βˆ’ 11

a 2 3 ( 64 ) βˆ’ 12 a Γ· 6 a 2 3 ( 64 ) βˆ’ 12 a Γ· 6

8 b βˆ’ 4 b ( 3 ) + 1 8 b βˆ’ 4 b ( 3 ) + 1

5 l Γ· 3 l Γ— ( 9 βˆ’ 6 ) 5 l Γ· 3 l Γ— ( 9 βˆ’ 6 )

7 z βˆ’ 3 + z Γ— 6 2 7 z βˆ’ 3 + z Γ— 6 2

4 Γ— 3 + 18 x Γ· 9 βˆ’ 12 4 Γ— 3 + 18 x Γ· 9 βˆ’ 12

9 ( y + 8 ) βˆ’ 27 9 ( y + 8 ) βˆ’ 27

( 9 6 t βˆ’ 4 ) 2 ( 9 6 t βˆ’ 4 ) 2

6 + 12 b βˆ’ 3 Γ— 6 b 6 + 12 b βˆ’ 3 Γ— 6 b

18 y βˆ’ 2 ( 1 + 7 y ) 18 y βˆ’ 2 ( 1 + 7 y )

( 4 9 ) 2 Γ— 27 x ( 4 9 ) 2 Γ— 27 x

8 ( 3 βˆ’ m ) + 1 ( βˆ’ 8 ) 8 ( 3 βˆ’ m ) + 1 ( βˆ’ 8 )

9 x + 4 x ( 2 + 3 ) βˆ’ 4 ( 2 x + 3 x ) 9 x + 4 x ( 2 + 3 ) βˆ’ 4 ( 2 x + 3 x )

5 2 βˆ’ 4 ( 3 x ) 5 2 βˆ’ 4 ( 3 x )

Real-World Applications

For the following exercises, consider this scenario: Fred earns $40 at the community garden. He spends $10 on a streaming subscription, puts half of what is left in a savings account, and gets another $5 for walking his neighbor’s dog.

Write the expression that represents the number of dollars Fred keeps (and does not put in his savings account). Remember the order of operations.

How much money does Fred keep?

For the following exercises, solve the given problem.

According to the U.S. Mint, the diameter of a quarter is 0.955 inches. The circumference of the quarter would be the diameter multiplied by Ο€ . Ο€ . Is the circumference of a quarter a whole number, a rational number, or an irrational number?

Jessica and her roommate, Adriana, have decided to share a change jar for joint expenses. Jessica put her loose change in the jar first, and then Adriana put her change in the jar. We know that it does not matter in which order the change was added to the jar. What property of addition describes this fact?

For the following exercises, consider this scenario: There is a mound of g g pounds of gravel in a quarry. Throughout the day, 400 pounds of gravel is added to the mound. Two orders of 600 pounds are sold and the gravel is removed from the mound. At the end of the day, the mound has 1,200 pounds of gravel.

Write the equation that describes the situation.

Solve for g .

For the following exercise, solve the given problem.

Ramon runs the marketing department at their company. Their department gets a budget every year, and every year, they must spend the entire budget without going over. If they spend less than the budget, then the department gets a smaller budget the following year. At the beginning of this year, Ramon got $2.5 million for the annual marketing budget. They must spend the budget such that 2,500,000 βˆ’ x = 0. 2,500,000 βˆ’ x = 0. What property of addition tells us what the value of x must be?

For the following exercises, use a graphing calculator to solve for x . Round the answers to the nearest hundredth.

0.5 ( 12.3 ) 2 βˆ’ 48 x = 3 5 0.5 ( 12.3 ) 2 βˆ’ 48 x = 3 5

( 0.25 βˆ’ 0.75 ) 2 x βˆ’ 7.2 = 9.9 ( 0.25 βˆ’ 0.75 ) 2 x βˆ’ 7.2 = 9.9

If a whole number is not a natural number, what must the number be?

Determine whether the statement is true or false: The multiplicative inverse of a rational number is also rational.

Determine whether the statement is true or false: The product of a rational and irrational number is always irrational.

Determine whether the simplified expression is rational or irrational: βˆ’18 βˆ’ 4 ( 5 ) ( βˆ’1 ) . βˆ’18 βˆ’ 4 ( 5 ) ( βˆ’1 ) .

Determine whether the simplified expression is rational or irrational: βˆ’16 + 4 ( 5 ) + 5 . βˆ’16 + 4 ( 5 ) + 5 .

The division of two natural numbers will always result in what type of number?

What property of real numbers would simplify the following expression: 4 + 7 ( x βˆ’ 1 ) ? 4 + 7 ( x βˆ’ 1 ) ?

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Chapter 2, Lesson 2: Comparing and Ordering Rational Numbers

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Chapter 10 Compare Real Numbers

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Lesson 10 Skills Practice Compare Real Numbers

Displaying top 8 worksheets found for - Lesson 10 Skills Practice Compare Real Numbers .

Some of the worksheets for this concept are Grade level 8th compare and order rational numbers, Practice your skills with answers, Reteach and skills practice, Name date period lesson 1 homework practice, Rational numbers, Comparing and ordering real numbers, Sets of numbers in the real number system, Multi part lesson 12 1 rational numbers.

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1. Grade Level: 8th 1. Compare and order rational numbers ...

2. practice your skills with answers, 3. reteach and skills practice, 4. name date period lesson 1 homework practice, 5. rational numbers -, 6. 1.4: comparing and ordering real numbers, 7. sets of numbers in the real number system, 8. multi-part lesson 12-1 rational numbers -.

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Lesson 10 Reteach Compare Real Numbers Answers

Lesson 10 Reteach Compare Real Numbers Answers - Displaying top 8 worksheets found for this concept.

Some of the worksheets for this concept are Reteach and skills practice, Rational numbers, Multi part lesson 12 1 rational numbers, Name date period lesson 3 skills practice, Name date period lesson 1 homework practice, Homework prractice and problem solving practice workbook, Work compare and order rational numbers, Name comparing and ordering real numbers work write.

Found worksheet you are looking for? To download/print, click on pop-out icon or print icon to worksheet to print or download. Worksheet will open in a new window. You can & download or print using the browser document reader options.

1. Reteach and Skills Practice

2. rational numbers -, 3. multi-part lesson 12-1 rational numbers, 4. name date period lesson 3 skills practice, 5. name date period lesson 1 homework practice, 6. homework prractice and problem-solving practice workbook, 7. worksheet compare and order rational numbers, 8. name: comparing and ordering real numbers worksheet write ....

IMAGES

  1. Lesson 10 Homework Practice Compare Real Numbers Answer Key

    lesson 10 problem solving practice compare real numbers

  2. Problem Solving: Compare Data Sets Worksheet for 5th Grade

    lesson 10 problem solving practice compare real numbers

  3. Multiplying multiples of 10 (problem solving) answer sheet

    lesson 10 problem solving practice compare real numbers

  4. Lesson 10 Homework Practice Compare Real Numbers Answer Key

    lesson 10 problem solving practice compare real numbers

  5. CLASSIFY, GRAPH & COMPARE REAL NUMBERS PowerPoint Mini-Lesson & Guided

    lesson 10 problem solving practice compare real numbers

  6. Compare And Order Real Numbers Worksheet

    lesson 10 problem solving practice compare real numbers

VIDEO

  1. Real Numbers

  2. Real Numbers

  3. Eureka Math Lesson 10 Problem Set

  4. Real Numbers

  5. Real Numbers

  6. 10th Real Numbers

COMMENTS

  1. Lesson 10 Compare Real Numbers Independant Practice

    Lesson 10 Compare Real Numbers Independant Practice - Displaying top 8 worksheets found for this concept.. Some of the worksheets for this concept are Lesson format resources, Hands on compare and order whole numbers, Homework practice and problem solving practice workbook, Multi part lesson 12 1 rational numbers, Sets of numbers in the real number system, Homework practice and problem solving ...

  2. Lesson 10 Skills Practice Compare Real Numbers

    Lesson 10 Skills Practice Compare Real Numbers. Lesson 10 Skills Practice Compare Real Numbers - Displaying top 8 worksheets found for this concept. Some of the worksheets for this concept are Grade level 8th compare and order rational numbers, Practice your skills with answers, Reteach and skills practice, Name date period lesson 1 homework ...

  3. Glencoe Math Course 3, Volume 1

    Section 1-10: Compare Real Numbers. Page 99: Vocabulary Check. Page 100: Key Concept Check. Page 101: Problem Solving. Page 102: ... Problem Solving. Page 258: Reflect. Page 259: Unit Project. Exercise 1. Exercise 2. Exercise 3. Exercise 4. ... With Expert Solutions for thousands of practice problems, you can take the guesswork out of studying ...

  4. Chapter 10 Compare Real Numbers Worksheets

    Chapter 10 Compare Real Numbers - Displaying top 8 worksheets found for this concept.. Some of the worksheets for this concept are Rational numbers, Grade level 8th compare and order rational numbers, Comparing and ordering real numbers, Name date period lesson 2 skills practice, Homework practice and problem solving practice workbook, Hands on compare and order whole numbers, Reteach and ...

  5. Comparing and Ordering Real Numbers

    Comparing and Ordering Real Numbers. Before diving into comparing and ordering real numbers, we start with reviewing the square roots of perfect squares and estimating square roots. As you likely know, number sense is crucial for being successful in a math classroom. This unit sets the foundation for the REST of the year. As a result, I have learned to take it slow and to do formative ...

  6. Lesson 10 Compare Real Numbers Independant Practice

    Displaying top 8 worksheets found for - Lesson 10 Compare Real Numbers Independant Practice. Some of the worksheets for this concept are Lesson format resources, Hands on compare and order whole numbers, Homework practice and problem solving practice workbook, Multi part lesson 12 1 rational numbers, Sets of numbers in the real number system, Homework practice and problem solving practice ...

  7. PDF Skills Practice Workbook

    001_009_CRM01_881031. Use the four-step plan to solve each problem. 1. GEOGRAPHY. The president is going on a campaign trip to California, first. flying about 2,840 miles from Washington, D.C., to San Francisco and. then another 390 to Los Angeles before returning the 2,650 miles back to.

  8. Lesson Explainer: Comparing and Ordering Real Numbers

    Lesson Explainer: Comparing and Ordering Real Numbers. Start Practising. In this explainer, we will learn how to compare and order numbers in ℝ. An ordered set is one in which we can compare any two elements of the set, π‘Ž and 𝑏, with one of three possible outcomes: π‘Ž and 𝑏 are equal, the order of π‘Ž is greater than that of 𝑏,

  9. Ordering Real Numbers ( Read )

    This lesson covers listing and comparing real numbers in order according to the directions given. ... Subsets of real number system. Simplify numbers before classifying ... Practice. Preview; Assign Practice; Preview. Progress % Practice Now. Algebra Real Numbers, Variables, and Expressions ..... All Modalities. More All Modalities; Share with ...

  10. Lesson 10 Compare Real Numbers Worksheets

    Lesson 10 Compare Real Numbers. Displaying all worksheets related to - Lesson 10 Compare Real Numbers. Worksheets are Hands on compare and order whole numbers, Working with circles, Algebra i readiness resources, Real numbers module 1, Math moves, Teksstaar based lessons, Teksstaar based lessons, Unit rate constant of proportionality 4 lessons.

  11. Ordering Real Numbers ( Read )

    Plot 1.25, 7 2, and 2 6 on a number line. One way to compare numbers is to use a number line. To plot these numbers, convert them all to decimals. 1.25, 7 2 = 3.5, and 2 6 β‰ˆ 4.899 (The symbol β‰ˆ means approximately.) Draw your number line and plot the points. Recall that 0 is called the origin.

  12. Comparing Numbers to 10 Worksheet (teacher made)

    Pupils can use this lovely worksheet to compare numbers up to 10. This resource allows them to use their fluency as well as reasoning and problem-solving skills. Check out this Money in Welsh Game - Bingo for more. Twinkl Key Stage 1 - Year 1, Year 2 Maths Number and Place Value Problem Solving. Pupils can use this lovely worksheet to compare ...

  13. Comparing Real Numbers Teaching Resources

    Comparing Real Numbers Card Game. Created by. Free to Discover. Students will practice comparing real numbers represented as radicals (square roots), repeating decimals, terminating decimals, fractions, and integers. All of the numbers are located between -6 and 6 to increase the challenge when comparing.

  14. Compare Real Numbers Lesson 10 Skills Practice

    Compare Real Numbers Lesson 10 Skills Practice - Displaying top 8 worksheets found for this concept.. Some of the worksheets for this concept are Sets of numbers in the real number system, Real numbers and number operations, Rational numbers, Reteach and skills practice, Multi part lesson 12 1 rational numbers, Comparing and ordering real numbers, Name date period lesson 8 skills practice ...

  15. Lesson 10 Extra Practice compare real numbers .pdf

    Course 3 β€’ Chapter 1 Real Numbers NAME _____ DATE _____ PERIOD _____ Lesson 10 Extra Practice Compare Real Numbers Name all sets of numbers to which each real number belongs. 1. 6.5 rational 2. 25 3. 3 irrational 4. 7.2 rational natural, whole, integer, rational 5. 0.61 rational 6. 1 2 rational 7. 16 4 8.

  16. 1.1 Real Numbers: Algebra Essentials

    The property states that, for every real number a, there is a unique number, called the multiplicative inverse (or reciprocal), denoted 1 a, that, when multiplied by the original number, results in the multiplicative identity, 1. a β‹… 1 a = 1. For example, if a = βˆ’ 2 3, the reciprocal, denoted 1 a, is βˆ’ 3 2 because.

  17. Chapter 2, Lesson 2: Comparing and Ordering Rational Numbers

    Real-World Careers California Standards Practice (STP) Vocabulary Review Lesson Resources ... Mathematics. Home > Chapter 2 > Lesson 2. California Mathematics: Concepts, Skills, and Problem Solving, Grade 7. Chapter 2, Lesson 2: Comparing and Ordering Rational Numbers. Extra Examples; Group Activity Cards; Personal Tutor; Self-Check Quizzes ...

  18. Quiz & Worksheet

    This worksheet and quiz let you practice the following skills: Making connections - use understanding of the concept of describing real numbers. Problem solving - use acquired knowledge to solve ...

  19. Chapter 10 Compare Real Numbers

    Displaying all worksheets related to - Chapter 10 Compare Real Numbers. Worksheets are Rational numbers, Grade level 8th compare and order rational numbers, Comparing and ordering real numbers, Name date period lesson 2 skills practice, Homework practice and problem solving practice workbook, Hands on compare and order whole numbers, Reteach and skills practice, Word problem practice workbook.

  20. Lesson 1 10 Compare Real Numbers Homework Practice

    Some of the worksheets for this concept are Real numbers and number operations, Name date period lesson 1 homework practice, Lesson numbers 1 10, Name date period lesson 9 homework practice, Problem solving name lesson problem solving, Answers lesson 1 1, Practice workbook grade 2 pe, Comparing and ordering rational numbers.

  21. Lesson 10 Skills Practice Compare Real Numbers

    Displaying top 8 worksheets found for - Lesson 10 Skills Practice Compare Real Numbers. Some of the worksheets for this concept are Grade level 8th compare and order rational numbers, Practice your skills with answers, Reteach and skills practice, Name date period lesson 1 homework practice, Rational numbers, Comparing and ordering real numbers, Sets of numbers in the real number system, Multi ...

  22. Lesson 10 Homework Practice Compare Real Numbersa0

    Lesson 10 Homework Practice Compare Real Numbersa0 - Displaying top 8 worksheets found for this concept.. Some of the worksheets for this concept are Rational numbers, Hands on compare and order whole numbers, Lesson format resources, Lesson 1 classification and real numbers, Homework practice and problem solving practice workbook, Notes unit 3 lesson 1 integers and absolute value, Rational ...

  23. Lesson 10 Reteach Compare Real Numbers Answers

    Lesson 10 Reteach Compare Real Numbers Answers - Displaying top 8 worksheets found for this concept.. Some of the worksheets for this concept are Reteach and skills practice, Rational numbers, Multi part lesson 12 1 rational numbers, Name date period lesson 3 skills practice, Name date period lesson 1 homework practice, Homework prractice and problem solving practice workbook, Work compare and ...