Lesson 2 - Section 8.2 Multiplying Integers

Name:______ Date: ______

Mathlinks 8

Lesson 2 - Section 8.2 Multiplying Integers

Review: Multiply the following. Use a model (integer chips) to help you complete each statement.

Integer Chips are coloured disks. ______disks represent +1. ______disks represent -

a) / b)
c) / d)


e) / a)

Use the results from the above to complete each statement.

When multiplying two integers with the SAME sign, the answer is ______.

When multiplying two integers with DIFFERENT signs, the answer is ______.

This is often called the SIGN RULE for MULTIPLICATION.

Example 1: Calculate the following. You can use the sign rule to help you out!

a) / b) / c) / d)

e) / f) / g) / h)

Sign Rule

The product of two integers with the same sign is positive. The product of two integers with different signs is negative.

Try. Calculate.

a)  b)

b)  d)

Try. Calculate.

a)  b)

c) d)

Try. Tina supports her favorite charity with an automatic deduction of $35/month from her bank account. Calculate the total of her deductions in a year?

Try. Duane instructs his bank to deduct $65 per month from his bank account and transfer the money into an investment account. What is the total of his deductions in 18 months?

Example 2: Mr. Marzouk instructs his bank to deduct $25 per month from his bank account and transfer the money into an investment account. What is the total of his deductions after 1 year?

Example 3: Without calculating the answers, identify the LEAST product and explain your thinking.

Example 4: Write a sign rule for the product of each of the following. You may want to make up some examples to support your answer.

a)  an even number of positive integers
/ b)  an odd number of positive integers




c)  an even number of negative integers
/ d)  an odd number of negative integers