1. Variable Expressions, Fixed Cost, Variable Cost

2. Objectives of the Day
SWBAT define a variable SWBAT represent a real life situation using variable expressions

3. variable
unknown
expression
no equal

4. TAKE OUT YOUR GRAPHIC ORGANIZERS
(Addition, Subtraction, Multiplication, Division)

5. 9-x 8x
5 - x
20÷x
x - 2 20 x 2x
x + 3
x - 5
x + 5

6. e b g h a f c d

7. Fixed Cost/Amount
Fixed Cost/Amount: a cost or amount that doesn’t change no matter what you do Examples: Flat fees, starting amounts, upfront costs, down payments, current savings, $_ off coupons, how much money you have
Throughout the Power Point, the titles on pages like this will be referred to as “structures.”
Throughout the Power Point, the titles on this type of slide will use language from the GLEs.
Other books/resources may use other names for the same structure. (Combine, Put Together)
At the beginning, it is not necessary for students to be able to name the structure of the problem.
Read the GLEs carefully to determine if, and when, students should be able to name the structure of basic word problems. 7

8. Variable Cost/Amount
Variable Cost/Amount: a cost or amount that changes depending on what you do to the variable [how much you buy, how many hours you work, etc.] Examples: Price per item, miles per hour, hourly wage, percent (%) of something, tax, tip, commission, etc.
Throughout the Power Point, the titles on pages like this will be referred to as “structures.”
Throughout the Power Point, the titles on this type of slide will use language from the GLEs.
Other books/resources may use other names for the same structure. (Combine, Put Together)
At the beginning, it is not necessary for students to be able to name the structure of the problem.
Read the GLEs carefully to determine if, and when, students should be able to name the structure of basic word problems. 8

9. Total Cost/Amount
Total Cost/Amount: the total cost or amount Examples: Total cost, total amount earned, total budget, total savings, etc.
Throughout the Power Point, the titles on pages like this will be referred to as “structures.”
Throughout the Power Point, the titles on this type of slide will use language from the GLEs.
Other books/resources may use other names for the same structure. (Combine, Put Together)
At the beginning, it is not necessary for students to be able to name the structure of the problem.
Read the GLEs carefully to determine if, and when, students should be able to name the structure of basic word problems. 9

10. Example 1
To place an ad in the Times-Picayune, there is a flat fee of $10 and an additional charge of $1.50 per line of text (t). Write an expression to show the total cost of placing an ad in the Times-Picayune.
Fixed Cost/Amount: Variable Cost/Amount: Variable:
Expression:
$10
$1.50 t
Throughout the Power Point, the titles on pages like this will be referred to as “structures.”
Throughout the Power Point, the titles on this type of slide will use language from the GLEs.
Other books/resources may use other names for the same structure. (Combine, Put Together)
At the beginning, it is not necessary for students to be able to name the structure of the problem.
Read the GLEs carefully to determine if, and when, students should be able to name the structure of basic word problems.
$1.50t + $10 10

11. Example 2
Michelle is going out to dinner with her family. Each meal cost 7 dollars and they have a coupon for $10 off. Write an expression to represent the cost of buying meals, m, at the restaurant.
Fixed Cost/Amount: Variable Cost/Amount: Variable:
Expression: -
$10 $7 m
Throughout the Power Point, the titles on pages like this will be referred to as “structures.”
Throughout the Power Point, the titles on this type of slide will use language from the GLEs.
Other books/resources may use other names for the same structure. (Combine, Put Together)
At the beginning, it is not necessary for students to be able to name the structure of the problem.
Read the GLEs carefully to determine if, and when, students should be able to name the structure of basic word problems.
$7m - $10 11

12. Example 3
Admission to Disneyland costs $80. Every meal costs $5 each. Write an expression to represent the total cost of eating meals at Disneyland.
Fixed Cost/Amount: Variable Cost/Amount: Variable:
Expression:
$80 $5 m
Throughout the Power Point, the titles on pages like this will be referred to as “structures.”
Throughout the Power Point, the titles on this type of slide will use language from the GLEs.
Other books/resources may use other names for the same structure. (Combine, Put Together)
At the beginning, it is not necessary for students to be able to name the structure of the problem.
Read the GLEs carefully to determine if, and when, students should be able to name the structure of basic word problems.
$5m + 80 12

13. Practice 1
Martha is planning to rent a limousine for a family reunion in Wales. The limousine service charges a fee of $40 plus $45 per hour. Write an expression to represent the situation.
Fixed Cost/Amount: Variable Cost/Amount: Variable:
Expression:
$40 h
$45
Throughout the Power Point, the titles on pages like this will be referred to as “structures.”
Throughout the Power Point, the titles on this type of slide will use language from the GLEs.
Other books/resources may use other names for the same structure. (Combine, Put Together)
At the beginning, it is not necessary for students to be able to name the structure of the problem.
Read the GLEs carefully to determine if, and when, students should be able to name the structure of basic word problems.
$45h + $40 13

14. Practice 2
Mary is making t-shirts, s, and she sells t-shirts for $12 per shirt. Mary has $20 in expenses. Write an expression to show her profit
Fixed Cost/Amount: Variable Cost/Amount: Variable:
Expression: -
$20 s
$12
Throughout the Power Point, the titles on pages like this will be referred to as “structures.”
Throughout the Power Point, the titles on this type of slide will use language from the GLEs.
Other books/resources may use other names for the same structure. (Combine, Put Together)
At the beginning, it is not necessary for students to be able to name the structure of the problem.
Read the GLEs carefully to determine if, and when, students should be able to name the structure of basic word problems.
$12s - $20 14

15. Whiteboard Practice Let’s review expectations for whiteboards:
Markers capped until the teacher says go
Only math-related work goes on the boards
Markers are only used to write on the boards
When the teacher says to, hold up your board - facing forward
Clean boards when finished

16. 1)
At the deli, po-boys with 8 ounces of meat cost $2.89. Extra meat is available for $0.25 per ounce. Write an expression to represent how much Greg will have to pay for a po-boy with m extra ounces of meat.
Fixed Cost/Amount: Variable Cost/Amount: Variable:
Expression:
$2.89 m
$0.25
Throughout the Power Point, the titles on pages like this will be referred to as “structures.”
Throughout the Power Point, the titles on this type of slide will use language from the GLEs.
Other books/resources may use other names for the same structure. (Combine, Put Together)
At the beginning, it is not necessary for students to be able to name the structure of the problem.
Read the GLEs carefully to determine if, and when, students should be able to name the structure of basic word problems.
$0.25m + $2.89 16

17. 2)
Carl is buying books at a book fair that cost $3 each and he has a coupon for $5 off. Write an expression that represents the cost of buying books, b, at the book fair.
Fixed Cost/Amount: Variable Cost/Amount: Variable:
Expression: $5 b $3
Throughout the Power Point, the titles on pages like this will be referred to as “structures.”
Throughout the Power Point, the titles on this type of slide will use language from the GLEs.
Other books/resources may use other names for the same structure. (Combine, Put Together)
At the beginning, it is not necessary for students to be able to name the structure of the problem.
Read the GLEs carefully to determine if, and when, students should be able to name the structure of basic word problems.
$3b - $5 17

18. 4)
Gledys goes to the mall to buy earrings. She brings $23 to the mall. Earrings (e) cost $3 per pair. Write an expression to show how much money, m, Gledys has left after buying earrings.
Fixed Cost/Amount: Variable Cost/Amount: Variable:
Expression:
$23 $3
Throughout the Power Point, the titles on pages like this will be referred to as “structures.”
Throughout the Power Point, the titles on this type of slide will use language from the GLEs.
Other books/resources may use other names for the same structure. (Combine, Put Together)
At the beginning, it is not necessary for students to be able to name the structure of the problem.
Read the GLEs carefully to determine if, and when, students should be able to name the structure of basic word problems. e
$23 - $3e 18

19. Example 8 – Check for Understanding
At a book fair, Scott bought a $4 tote bag and some books for $2 each. The total amount Scott spent is represented by the expression 2x + 4. What does the variable x represent?
the number of books
Throughout the Power Point, the titles on pages like this will be referred to as “structures.”
Throughout the Power Point, the titles on this type of slide will use language from the GLEs.
Other books/resources may use other names for the same structure. (Combine, Put Together)
At the beginning, it is not necessary for students to be able to name the structure of the problem.
Read the GLEs carefully to determine if, and when, students should be able to name the structure of basic word problems. 19

20. Example 9 – Check for Understanding
Noel is a computer repairman. To fix a computer, he charges a customer $40 per hour, plus a fixed fee of $15 for the service call, as represented by the expression 40x What does the variable x represent?
the number of hours
Throughout the Power Point, the titles on pages like this will be referred to as “structures.”
Throughout the Power Point, the titles on this type of slide will use language from the GLEs.
Other books/resources may use other names for the same structure. (Combine, Put Together)
At the beginning, it is not necessary for students to be able to name the structure of the problem.
Read the GLEs carefully to determine if, and when, students should be able to name the structure of basic word problems. 20

21. Wrap it Up (5 min)
A few students from Ms. Finley’s class decide to go bowling. They figure out the total cost of their trip bowling will follow the formula:
$25h + $10
What might the $25 mean?
What might the h mean?
What might the $10 mean?

22. Weird EOC Question! L = _________________ w
The length of the rectangle is 4 more than the width.
Throughout the Power Point, the titles on pages like this will be referred to as “structures.”
Throughout the Power Point, the titles on this type of slide will use language from the GLEs.
Other books/resources may use other names for the same structure. (Combine, Put Together)
At the beginning, it is not necessary for students to be able to name the structure of the problem.
Read the GLEs carefully to determine if, and when, students should be able to name the structure of basic word problems.
L = w + 4 22

23. Weird EOC Question! L = _________________ w
2. The length of the rectangle is 4 less than the width.
Throughout the Power Point, the titles on pages like this will be referred to as “structures.”
Throughout the Power Point, the titles on this type of slide will use language from the GLEs.
Other books/resources may use other names for the same structure. (Combine, Put Together)
At the beginning, it is not necessary for students to be able to name the structure of the problem.
Read the GLEs carefully to determine if, and when, students should be able to name the structure of basic word problems.
L = w - 4 23

24. Weird EOC Question! L = _________________ w
3. The length of the rectangle is 4 more than 2 times the width.
Throughout the Power Point, the titles on pages like this will be referred to as “structures.”
Throughout the Power Point, the titles on this type of slide will use language from the GLEs.
Other books/resources may use other names for the same structure. (Combine, Put Together)
At the beginning, it is not necessary for students to be able to name the structure of the problem.
Read the GLEs carefully to determine if, and when, students should be able to name the structure of basic word problems.
L = 2w + 4 24

25. Weird EOC Question! L = _________________ w
4. The length of the rectangle is twice the width.
Throughout the Power Point, the titles on pages like this will be referred to as “structures.”
Throughout the Power Point, the titles on this type of slide will use language from the GLEs.
Other books/resources may use other names for the same structure. (Combine, Put Together)
At the beginning, it is not necessary for students to be able to name the structure of the problem.
Read the GLEs carefully to determine if, and when, students should be able to name the structure of basic word problems.
L = 2w 25

26. Weird EOC Question! L = w 2 L = _________________ w
5. The length of the rectangle half the width.
Throughout the Power Point, the titles on pages like this will be referred to as “structures.”
Throughout the Power Point, the titles on this type of slide will use language from the GLEs.
Other books/resources may use other names for the same structure. (Combine, Put Together)
At the beginning, it is not necessary for students to be able to name the structure of the problem.
Read the GLEs carefully to determine if, and when, students should be able to name the structure of basic word problems.
L = w 2 26

27. Weird EOC Question! L = _________________ w
6. The length of the rectangle is 4 more than 5 times the width.
Throughout the Power Point, the titles on pages like this will be referred to as “structures.”
Throughout the Power Point, the titles on this type of slide will use language from the GLEs.
Other books/resources may use other names for the same structure. (Combine, Put Together)
At the beginning, it is not necessary for students to be able to name the structure of the problem.
Read the GLEs carefully to determine if, and when, students should be able to name the structure of basic word problems.
L = 5w + 4 27

28. Weird EOC Question! L = _________________ w
7. The length of the rectangle is 10 less than 11 times the width.
Throughout the Power Point, the titles on pages like this will be referred to as “structures.”
Throughout the Power Point, the titles on this type of slide will use language from the GLEs.
Other books/resources may use other names for the same structure. (Combine, Put Together)
At the beginning, it is not necessary for students to be able to name the structure of the problem.
Read the GLEs carefully to determine if, and when, students should be able to name the structure of basic word problems.
L = 11w - 10 28

29. Weird EOC Question! L = _________________ w
7. The length of the rectangle is 5 more than twice the width.
Throughout the Power Point, the titles on pages like this will be referred to as “structures.”
Throughout the Power Point, the titles on this type of slide will use language from the GLEs.
Other books/resources may use other names for the same structure. (Combine, Put Together)
At the beginning, it is not necessary for students to be able to name the structure of the problem.
Read the GLEs carefully to determine if, and when, students should be able to name the structure of basic word problems.
L = 2w + 5 29