Solving 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 terms and then solve for the unknown variable.

Front

If 4 pizzas require 8 lbs of cheese, how much cheese is needed for 1 pizza?

Back

2 lbs of cheese.

Front

If I need 5 cups of flour to make 3 pies, how many pies can I make with 25 cups of flour?

Back

15 pies.

Front

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

Back

If a/b = c/d, then ad = bc.

Front

If 24 cookies are shared among 3 classes, how many cookies does each class get?

Back

8 cookies per class.

Front

If a recipe calls for 2 cups of sugar for 4 servings, how much sugar is needed for 10 servings?

Back

5 cups of sugar.

Front

What is the relationship between the quantities in a proportion?

Back

The quantities in a proportion are equivalent when expressed as ratios.

Front

If 3 apples cost $1.50, how much do 12 apples cost?

Back

$6.00.

Front

What is the cross-multiplication method?

Back

Cross-multiplication involves multiplying the numerator of one ratio by the denominator of the other ratio.