Ratio, Percent, Proportion

EQ: How do you use standard ratio notation for expressing ratios?

(3:5, 3 to 5, 3/5)OBJ: 1.01

A ratio is a comparison of two numbers by divisionIf a gallon of paint contains 2 parts blue

paint and 4 parts yellow paint, then the ratio comparing blue paint to yellow paint would be

2 to 4, 2 : 4, 2/4REMEMBER to simplify when possible

2/4 = ½

9 goldfish out of 15 fish9/15 3/5 *This means that for every 5 fish, 3 of

them are goldfish

Ratio:

Express the ratio as a fraction

When writing a ratio involving measurements, both quantities should have the same unit of measurement.

3 feet to 16 inches 3feet convert to inches 36

inches 16 inches 16 inches

Simplify 9 inches 4 inches 9 to 4

IMPORTANT

Express the ratio as a fraction

A rate is a ratio of two measurements having different kinds of units.

65 miles in 3 hours $16 for 2 pounds

When a rate is simplified, so that it has

a denominator of 1, it is called a unit rate. An example of a unit rate is $5 per

pound, which means $5 per 1 pound

Rate:

Unit Rate

A package of 20 recordable CDs costs $18, and a package of 30 recordable CDs costs $28. Which package has the lower cost per CD?

18 dollars = 0.9 dollars20 CDs 1 CD for the 20-pack, the unit rate is $0.90 per CD.

28 dollars = 0.93 dollars30 CDs 1 CD for the 30-pack, the unit rate is $0.93 per CD

So, the package that contains 20 CDs has the lower cost per CD

Find and compare unit rates

A grizzly bear can run 30 miles in 1 hour. How many feet is this per second?

*You need to convert 30 mi to Xft. 1 hr 1 sec**There are 5,820 feet in 1 mile and 3600 seconds in 1

hour. 30mi. = 30 mi * 5280 ft ÷ 3600 s 1 hr 1 hr 1 mi 1 hr

Cancel out and multiply across

= 44 ft 1 secSo, 30 miles per hour is equivalent to 44 feet

per second

Convert Rates