Ratios and Proportions

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 simplify a ratio?

Back

To simplify a ratio, divide both terms by their greatest common divisor (GCD).

Front

What is a proportion?

Back

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

Front

If the ratio of boys to girls in a class is 2:3, how many boys are there if there are 15 girls?

Back

There are 10 boys. (Using the ratio 2:3, if 3 parts = 15 girls, then 2 parts = 10 boys.)

Front

What is the scale in a scale drawing?

Back

The scale is the ratio of a distance on the drawing to the actual distance it represents.

Front

If a scale drawing has a scale of 1 cm:5 m, how many meters does 3 cm represent?

Back

3 cm represents 15 m.

Front

What is an equivalent ratio?

Back

Equivalent ratios are two or more ratios that express the same relationship between numbers.

Front

How do you find an equivalent ratio?

Back

To find an equivalent ratio, multiply or divide both terms of the ratio by the same non-zero number.

Front

If there are 4 apples for every 5 oranges, how many apples are there if there are 20 oranges?

Back

There are 16 apples. (Using the ratio 4:5, if 5 parts = 20 oranges, then 4 parts = 16 apples.)

Front

What is the unit rate?

Back

The unit rate is a ratio that compares a quantity to one unit of another quantity.