Writing ratios

Math

Definition

Writing ratios means expressing the relationship between two or more quantities as a comparison. Ratios can be written in three forms: using a colon (3:4), as a fraction (3/4), or with the word 'to' (3 to 4).

Examples

  • If a class has 12 boys and 18 girls, the ratio of boys to girls is 12:18 or simplified 2:3
  • A recipe calls for 2 cups flour to 1 cup sugar, written as 2:1
  • In a bag with 5 red and 3 blue marbles, the ratio of red to total is 5:8
Key Fact

Ratios should always be simplified to lowest terms, like fractions

Related Terms

Unit rates Solving proportions Simplifying rational expressions

Study This Concept

Practice writing ratios with free review games in these units:

Pre-Algebra Unit 3: Ratios and Proportions