1. Variables and Patterns
Unit Test Review

2. Write an equation for each situation:
Carl drives 43 miles in one hour. (Use d for distance and t for time.)
Sara has $400 and saves $40 every month. (Use s for total savings and t for time.)
Craig has $500 and spends $100 a month. (Use t for money left and t for time.)
Sandra earns $7 each hour. (Use t for time and e for total earnings.)

3. d = 43t
2) s = t
t = 500 – 100t
e = 7t

4. Jack buys fifty baseball cards every month. What is the IV and the DV?
What is the pattern of change?
How would you see the pattern of change in
A table?
A graph?
An equation?

5. IV = time in months; DV = total number of cards
As time increases by one month, baseball cards increase by fifty.
Table- differences would be the same (50)
Graph- you’d see a straight line because every time you move right one on the x-axis, you move up 50 on the y-axis.
Equation- the coefficient is 50

6. What is a coefficient?

7. The coefficient is the number that you are multiplying by a variable
The coefficient is the number that you are multiplying by a variable. It is usually in front of it, but without a multiplication sign.
In an equation, the coefficient tells you the “thing” that gets repeated. Often key words are every, each, or per.
For example, Kevin has 50 stamps. He adds 3 to his collection every year. s = t

8. In the Rocky and Adrian problem in our text, what was the pattern of change for Rocky’s shop?

9. As number of bikes increases, the total cost increases but not at a steady pace.

10. In the Rocky and Adrian problem in our text, what was the pattern of change for Adrian’s shop?

11. As number of bikes increase by 5, the total cost increases by $150.OR
As number of bikes increase by 1, the total cost increases by $30.

12. In the Rocky and Adrian problem, why does Adrian’s data turn into a straight line?

13. It’s a straight line because it’s a steady increase
It’s a straight line because it’s a steady increase. That is, every time you move right one on the x-axis, you move up 30 on the y-axis.

14. If you have a graph with the following labels:
IV = number of cars
DV = total weight (pounds)
would it make sense to connect the points?

15. No, because cars are discrete data
No, because cars are discrete data. You can’t break a car into smaller parts and still have it make sense.

16. Consider the following table:
What is the first ordered pair?
What does the ordered pair represent?
What is the fourth ordered pair?
Time (weeks) 1 2 3 4
Weight
(pounds) 12 24 36 48

17. The first ordered pair is (0,0)
The first ordered pair is (0,0). The numbers mean that at 0 weeks, the weight is 0 pounds.
The fourth ordered pair is (3,36). The numbers mean that at 3 weeks, the weight is 36 pounds.

18. Hopefully you found this to be a helpful review for Thursday’s unit test. To help you even more:
Review the unit test study guide that is on my website
Review homework, classwork, notes and old quizzes/miniquizzes
Look at any ACE problems you have worked on already
Check out any answer keys or that are on my website you might have
Maybe form a study group with a friend/friends?