Multiplying and Dividing Integers

Read this text. Pay special attention to the sections Multiplication of Signed Numbers and Division of Signed Numbers. These sections give summaries of the rules for multiplying and dividing positive and negative integers. Complete the practice questions and check your answers.

Examples

Solutions

Example 3.47

Multiply each of the following:

ⓐ −9⋅3
ⓑ −2(−5)
ⓒ 4(−8)
ⓓ 7⋅6

 Solution

ⓐ  –9⋅3
Multiply, noting that the signs are different and so the product is negative.

–27

ⓑ  –2(–5)
Multiply, noting that the signs are the same and so the product is positive.

10

ⓒ 4(–8)
Multiply, noting that the signs are different and so the product is negative.

–32

ⓓ  7⋅6
The signs are the same, so the product is positive.

42


Example 3.49

Divide each of the following:

ⓐ −27÷3
ⓑ −100÷(−4)

Solution

ⓐ  –27÷3
Divide, noting that the signs are different and so the quotient is negative.

–9

ⓑ  –100÷(–4)
Divide, noting that the signs are the same and so the quotient is positive.

25


Try It 3.93
    ⓐ −48
    ⓑ 28
    ⓒ −63
    ⓓ 60


Try It 3.94
    ⓐ −56
    ⓑ 54
    ⓒ −28
    ⓓ 39


Try It 3.95
    ⓐ −9
    ⓑ 17


Try It 3.97
    ⓐ −7
    ⓑ 39

Try It 3.98
    ⓐ −9
    ⓑ 23