Chapter 2 Review

Chapter 2-Fractions and Decimals

Review

Section 2.1

Multiplying Fractions

Key Idea

• Multiply the numerators and multiply the denominators.

•  $\frac{3}{7}\times\frac{1}{2}=\frac{3\times1}{7\times2}=\frac{3}{14}$  

•  $\frac{a}{b}\cdot\frac{c}{d}=\frac{a\cdot c}{b\cdot d},\ where\ b,\ d\ \ne0$  

Multiplying Mixed Numbers

Write each mixed number as an improper fraction. Then multiply as you would with fractions.

Fill in the Blanks

 $1\frac{1}{3}\cdot\frac{2}{3}$  

Fill in the Blanks

 $\frac{1}{7}\cdot\frac{2}{3}$  

Fill in the Blanks

 $6\cdot\frac{7}{8}$  

Fill in the Blanks

 $15\cdot2\frac{4}{9}$  

Section 2.2

Dividing Fractions

Vocabulary

• Reciprocals - Two numbers whose product is 1

• Multiplicative Inverses - Two numbers whose product is 1

Key Idea

• To divide a number by a fraction, multiply the number by the reciprocal of the fraction.

•  $\frac{1}{5}÷\frac{3}{4}=\frac{1}{5}\times\frac{4}{3}=\frac{1\times4}{5\times3}$  

•  $\frac{a}{b}÷\frac{c}{d}=\frac{a}{b}\cdot\frac{c}{d}=\frac{a\cdot c}{b\cdot d},\ wehre\ b,\ c,\ and\ d\ \ne0$  

Fill in the Blanks

 $\frac{1}{3}÷\ \frac{1}{2}$  

Fill in the Blanks

 $\frac{6}{5}÷3$  

Fill in the Blanks

 $10÷\frac{5}{12}$  

Fill in the Blanks

You use  $\frac{1}{8}$  of your battery for every  $\frac{2}{5}$  of an hour that you video chat.  You use  $\frac{3}{4}$  of your battery video chatting.  How long did you video chat?

Section 2.3

Dividing Mixed Numbers

Key Idea

Write each mixed number as an improper fraction. Then divide as you would with proper fractions.

Fill in the Blanks

 $2\frac{1}{4}÷\frac{3}{4}$  

Fill in the Blanks

 $8\frac{4}{7}÷15$  

Fill in the Blanks

A platinum nugget weighs  $3\frac{1}{2}$  ounces.  How many  $\frac{1}{4}$  ounce pieces can be cut from the nugget?

Section 2.4

Adding and Subtracting Decimals

Key Idea

To add or subtract decimals, write the numbers vertically and line up the decimal points. Then bring down the decimal point and add or subtract as you would with whole numbers.

Fill in the Blanks

7.82+3.209

Fill in the Blanks

11.212+7.36

Fill in the Blanks

41.226+102.774

Fill in the Blanks

4.58-3.12

Fill in the Blanks

8.629-5.309

Fill in the Blanks

152.883-35.6247

Fill in the Blanks

Vehicles must weigh no more than 10.75 tons to cross a bridge. A truck weighs 11.638 tons. By how many tons does the truck exceed the weight limit?

Section 2.5

Multiplying Decimals

Key Idea

• Multiply as you would with whole numbers. Then count the number of decimal places in the decimal factor. The product has the same number of decimal places.

•  $13.91\times7=97.37\$  Notice that there are 2 decimal places in both the problem and the solution.

Fill in the Blanks

 $4.8\times7$  

Fill in the Blanks

 $7.19\times16$  

Fill in the Blanks

 $0.007\times0.03$  

Fill in the Blanks

The weight of an object on the Moon is about 0.167 of its weight on Earth. How much does a 180-pound astronaut weigh on the moon?

Section 2.6

Dividing Whole Numbers

Fill in the Blanks

837÷27

Fill in the Blanks

6409÷61

Fill in the Blanks

6200÷163

Fill in the Blanks

A pharmacist divides 364 pills into prescription bottles. Each bottle contains 28 pills. How many bottles does the pharmacist fill?

Section 2.7

Dividing Decimals

Key Idea

• Place the decimal point in the quotient above the decimal point in the dividend. Then divide as you would with whole numbers. Continue until there is no remainder.

Key Idea

Multiply the divisor and the dividend by a power of 10 to make the divisor a whole number. Then place the decimal point in the quotient above the decimal point in the dividend and divide as you would with whole numbers. Continue unitl there is no remainder

Fill in the Blanks

25.2÷6

Fill in the Blanks

10.4÷8

Fill in the Blanks

36.47÷0.7

Fill in the Blanks

56.7175÷4.63

Fill in the Blanks

A person's running stride is about 1.14 times the person's height. Your friend's stride is 5.472 feet. How tall is your friend?

Fill in the Blanks

You have 3.4 gigabytes available on your tablet. A song is about 0.004 gigabyte. How many songs can you download onto your tablet?