1. 6.2 – More Patterns and Expressions
Grade 5 – Write and evaluate expressions involving multiplication, addition, and subtraction

2. Set the Purpose
You have already evaluated numerical and algebraic expressions. Today you will learn how to evaluate algebraic expressions with more than one operation.

3. Pose the Problem
The rental car company charges 40 BD as a base to rent a car and 2 BD for every kilometer driven. How much would it cost to rent a car and drive 30 kilometers?
What information are you given to solve this problem?
How can you use this information to find the total cost of the rental?
What expression can you write to show this?

4. Continued
The rental car company charges 40 BD as a base to rent a car and 2 BD for every kilometer driven. How much would it cost to rent a car and drive 30 kilometers?
Final Cost __________________
Cost for Kilometers Driven ____________
Kilometers Driven 30 40 75
100

5. Word Problem Bob’s Electrical Repair $55 Fee $65 per hour
The total cost is the fee plus the charge per hour times the number of hours.
Write an expression for the total cost. Let H represent the number of hours.

6. Word Phrases & Algebraic Expressions
Word Phrase Algebraic Expression
Five times a number, plus two
Two less than five times a number
Two more than five times a number
Two minus five times a number

7. TIP
Sometimes a word phrase can be interpreted in different ways. The word phrase below can be interpreted in two different ways. Parentheses are used to make the algebraic expressions clear.
Word Phrase: five times a number plus 2
Algebraic Expressions: (5 x n) + 2, or 5 x (n + 2)

8. Practice Three times a number, plus 10 Four less than a number times 2
Eight plus a number times 5
Forty minus two times a number

9. Practice Nine times a number, minus six
Seven less than a number times three
Four more than a number, times twelve
Eight plus a number times sixteen

10. Practice Evaluate the expression for r = 6 and h = 42 (8 + r ) x 3
9r – 2h

11. Homework
6.3 Worksheet