Double Number Line for Modeling

Overview of Equivalent Ratios

Formative Assessment

Summary of the Math: Overview of Equivalent Ratios

Read and Discuss

  • A ratio is often represented as a pair of numbers, either in colon notation (280:210 or 4:3) or as a fraction (280210=43).
  • You can determine whether two ratios are equivalent in the following way:
    The ratios 2:3 and 4:6 are equivalent if 23=46.
  • You can represent equivalent ratios using a double number line. A double number line shows the relationship between two quantities by lining up the quantities at the same tick marks. Each of these pairs of numbers represents a ratio, and all of the ratios on a given double number line are equivalent; that is, the ratios all have the same value.

Can you:

  • Find equivalent ratios?
  • Represent equivalent ratios on a double number line?