Lesson 3.1 Ratio

Lesson 3.1 - Ratios

​New Vocabulary

​Ratio - a comparison of two quantities. Ratios can be part-to-part, part-to-whole, or whole-to-part comparisons.

​The ratio a : b indicates that there are a  units of the first quantity for every b units of the second quantity.

​Examples:

• 2 cats to 6 dogs

• 1 cat for every 3 dogs

• 3 dogs for each cat

• 3 dogs out of every 4 pets

• 2 cats out of 8 pets

The ratio of a to b can be written as a : b

​Example 1

1. Write the ratio of pennies to quarters.

2. Write the ratio of quarters to dimes.

3. Write the ratio of dimes to the total number of coins.​