# Multiplication and Division of Integers and Rational Numbers

Develop rules for and understanding multiplication and division signed integers

Multiplication of Integers - Counters

Rules for multiplication of signed integers  Assignment:

Glencoe: 54-55 (1-6, 17-30)

Exercise 1: Multiplication of Integers in the Real-World

Generate real-world situations that can be modeled by the following expressions:

a. −3 × 5
b. −6 × (−3)
c. 4 × (−7)

Exercise 2: Word Problem

Each time that Samantha rides the commuter train, she spends \$4 for her fare. Write an expression that represents the change in Samatha’s money from riding the commuter train to and from work for 14 days, then, solve.

Rules for signed division of integers

Assignment:

Glencoe: 54-55 (7-12, 31-40)

Understanding multiplication and division of rational numbers

Multiplication of signed rational numbers

Example 1: Using the Commutative and Associative Properties to Efficiently Multiply Rational Numbers
a. Evaluate the expression below:

−6 × 2 × (−2) × (−5) × (−3)

b. What types of strategies were used to evaluate the expressions?

c. Can you identify the benefits of choosing one strategy versus another?

d. What is the sign of the product and how was the sign determined?

Exercise 1: Find an efficient strategy to evaluate the expression and complete the necessary work.

−1 × (−3) × 10 × (−2) × 2

Exercise 2: Find an efficient strategy to evaluate the expression and complete the necessary work. What terms did you combine first and why?

Example 3: Using the Distributive Property to Multiply Rational Numbers
Evaluate using the distributive property. Assignment: Multiplication: Glencoe: 99-100 (1-48 odd)

Division of signed rational numbers

Glenco: 2-4 Ex2-5

Assignment: Division: Glencoe: 105-106 (1-45 odd)

Example 4  Assessment