Proportions

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 two ratios and set the products equal to each other.

Front

What is the formula for finding a missing value in a proportion?

Back

If a/b = c/d, then ad = bc. You can find the missing value by rearranging this equation.

Front

If 3/4 = x/20, what is x?

Back

x = 15.

Front

What is a ratio?

Back

A ratio is a comparison of two quantities by division.

Front

How do you express a ratio?

Back

A ratio can be expressed in three ways: as a fraction, with a colon (3:4), or with the word 'to' (3 to 4).

Front

What is the relationship between ratios and proportions?

Back

Ratios are used to compare two quantities, while proportions show that two ratios are equal.

Front

If a recipe calls for 2 cups of flour for every 3 cups of sugar, what is the ratio of flour to sugar?

Back

The ratio of flour to sugar is 2:3.

Front

If 5 boys are to 3 girls, how many girls are there if there are 15 boys?

Back

There are 9 girls.

Front

What is the unit rate?

Back

The unit rate is a comparison of two different quantities when they are combined together, expressed as a quantity of one.