Solving Proportions Solving Proportions

Using Unit RatesUsing Unit Rates

Objective:

We will learn to use unit rates to solve a proportion.

* Solving a proportion means finding a missing part of the proportion..

Steps:

1. Divide to find the unit rate.

2. Multiply the unit rate by the

number in question to solve the

proportion.

For Example: 5 CD’s cost $42 dollars, how much will 7 CD’s cost?

• First you have to divide: $42 ÷ 5 to find the unit rate. Your answer is 8.4 which equals $8.40.

This means that: $42 = $8.40 This is the unit rate. 5cd 1cd Once you have found the unit rate, you have to multiply it

by the number they are asking you to find in the problem.

If it costs $8.40 for 1 CD then $8.40 × 7CDs = $58.80

• Answer: $58.80 dollars for 7CD’s.

Example 2: Find the unit rate: 24 pages in 6 minutes.Find how many pages in 10 minutes.

First, Divide 24 pages = 4 pages (This is the unit rate.) 6min. 1 min.

•Second, You multiply 4 pages×10 minutes = 40 pages in 10 min or 40 pages 10 min

Your Example: Your Example: Alejandro was paid $40.00 for 5 hours of Alejandro was paid $40.00 for 5 hours of work. If he gets paid by the hour, how work. If he gets paid by the hour, how much will he be paid for 12 hours of work?much will he be paid for 12 hours of work?(Hint: First find the unit rate. Then find how (Hint: First find the unit rate. Then find how much in 12 hours.) much in 12 hours.)

Homework:find the unit rate, then you multiply to find the answer of the problem. . 1. Bananas are on sale 8

for $3.20, find the cost of 1 banana. Then find the cost of 7 bananas.

2. Andres earned $199.50 for 24 hours of work. Find his hourly rate. Find his earnings for 15 hours of work.

3. 4 notebooks cost $12, how much does 1 notebook cost? How much do 9 notebooks cost?

4. 4. Cans of soup are sold at 3 for $2 dollars. How much does 1 can cost? How much do 5 cans cost?

5. A 4-ounce raw tomato has 24 calories. Find the unit rate in calories per ounce. Find how many calories in 16 ounces of tomatoes.