# Ratios and Proportions / What is a Ratio?

Activity 1 of 15
This lesson helps students to understand that ratios associate two or more quantities that vary together.

## Planning and Resources

Objectives
Students should understand and be able to explain that ratios are an association of two or more quantities.

Vocabulary
ratio
equivalent ratio

Standard:

## Lesson Snapshot

#### The Big Idea

What is a ratio and when are two ratios equivalent?

### What are the students doing?

Students discuss the similarities and differences between the groups of shapes that illustrate equivalent ratios.

### What is the teacher doing?

Reinforce the definition of equivalence by associating the patterns generated with the original ratio.

#### Understanding

The questions introduce students to the concept of a ratio as paired quantities that vary together in the same relationship. This leads to the notion of equivalent ratios.

### What to look for

Students should explore how changing the ratio of circles to squares affects corresponding equivalent ratios.

### Sample Assessment

Which of the following pairs of ratios are equivalent?
a. 6:3 and 5:10
b. 6:3 and 3:6
c. 6:3 and 12:6
d. 3:1½ and 6:3