1. Chapter 5 Ratios, Rates, Proportions

2. Ratios A ratio is a comparison of two quantities by division
There are three ways to write a ratio:
Using the word “to”
5 to 24
Using a colon “:”
5 : 24
Using a fraction 5 24
Two ratios that name the same number are equal ratios

3. Warm-Up Write each fraction in simplest form. 1. 3/9 2. 15/25 3. 45/54
1. 3/ / /54
4. 14/ / /204

4. Ratios cont’d
Ex. Two students report the ratio of the number of girls in a class to the total number of students. One student says the ratio is 18/30. The other says the ratio is 9/15. The two ratios are equal.
Ex. Find two ratios equal to 12 15
12 x 2 = ÷ 3 = 4
15 x ÷

5. Ratios cont’d To write a ratio as a decimal, divide
Ex. 5 to 12, 5 : 12, 5 12
= 0.416…
To write a ratio in simplest form, divide the numerator and the denominator by the GCF
Ex ÷ 3 = 4
15 ÷

6. Unit Rates A unit rate is the rate for one given quantity
*unit price is the same as unit rate(just deals with money)
Ex. Determine the unit rate if a car travels 120 miles in 2 hours.
***Hint***-you want to know how many miles the car travels in “1” hour
*** the unit rate is 60 miles/1 hour or 60 miles/hour

7. Example(s) of Unit Rates/Prices
1.) 40miles/gal 4.) $1.59/lb
2.) 5yds/min 5.) $24.99/dozen
miles/hour 6.) $3.19/gal

8. Proportions
A proportion is an equation stating that two ratios are equal
For two ratios, the cross products are found by multiplying the denominator of each ratio by the numerator of the other ratio
***Hint***-to solve proportions “cross multiply” or “orbit”
***after you “orbit” you have a one-step equation