Ratios

Front

What is a ratio?

Back

A ratio is a comparison of two quantities by division, showing how many times one value contains or is contained within the other.

Front

How do you write a ratio?

Back

Ratios can be written in three ways: as a fraction (e.g., 5/7), with a colon (e.g., 5:7), or in words (e.g., 5 to 7).

Front

What is a proportion?

Back

A proportion is an equation that states that two ratios are equal.

Front

How do you solve a proportion?

Back

To solve a proportion, cross-multiply the terms and then solve for the unknown.

Front

What is the constant of proportionality?

Back

The constant of proportionality is the constant value (k) that relates two proportional quantities, often found by dividing one quantity by the other.

Front

If a car travels 280 miles in 7 hours, what is the constant of proportionality for distance traveled per hour?

Back

The constant of proportionality is 40 miles per hour (280 miles ÷ 7 hours).

Front

How do you find the ratio of girls to boys if there are 5 boys and 7 girls?

Back

The ratio of girls to boys is 7 to 5.

Front

What is the formula for finding the total distance traveled if speed and time are known?

Back

Distance = Speed × Time.

Front

If Craig earns $37 for 4 hours, how much does he earn per hour?

Back

He earns $9.25 per hour ($37 ÷ 4 hours).

Front

What is the relationship between distance, speed, and time?

Back

Distance varies directly with time when speed is constant.