Sewanhaka High School Mrs. Lidowsky, Principal
Math 8 Mr. Long, Teacher
Name:__________________________ Per: ____ Date: _____________________
H.W. #19: Ditto
DO-NOW #19: Express each ratio or fraction as a percent:
1) Express the following ratio in simplest form: 8 out of 12 =
2) Express the following rate as a unit rate: $17.40 in 3 hours =
3) Evaluate:
(a) 12 – 8 / 4 + 2 =
(b) (12 – 8) / (4 + 2) =
(c) (12 – 8) / 4 + 2 =
4) Dorothy as a measuring cup that can hold a maximum of 2
3 of a cup. How many times will Dorothy fill her measuring cup with flour to measure 3 1
3
cup?
Topic: Expressions and Equations
Main Idea: Solving Proportions
Aim:
RECALL NOTES
( ) bought a brand new house with the LOTTO money he won. To keep the trespassers out, (
) wants to set up electrical fencing around the house (very low current of course). Landz paid $200 for
400 square feet of fencing they had left. ( ) still needs to buy another 200 square feet of fencing.
Question: What is a proportion? A proportion is an ___________ that states that two r__________ are e_______________.
Question: How much will the 200 feet of fencing cost?
Question: Is the equation
200 sq.
ft.
400 sq.
ft.
why not?

$ 100
$ 200 true? Why or
Question: Determine whether 9
12 and 18
24 form a proportion.
Question: Does 9:12 = 6 : 8?
(Use a proportion to find your answer.)
Question: Solve the proportion 3
7

21 d

Drill: Determine whether each pair of ratios form a proportion.
16
1)
12
,
12
9
2)
3
11
,
55
200
3) 2 : 4 = 6 : 8 4) 5 : 2 = 20 : 4 r
3) Solve the following proportions: a)
9
6
=
27
b) b) 4 : w = 3 : 9
4)
LIFE SCIENCE FACT:
When a robin flies, it beats its wings an average of 23 times in 10 seconds. How many times will its wings beats in 120 seconds? How many times will its wings beats in 2 minutes?
SUMMARY:
If time: List two ratios that do not form a proportion. Explain why they do not.