Scale Unit Fractions on a Double-Sided Number Line: Part I 5-86
Use double-sided number lines to visualize and scale unit-fractions proportionally. If 2 pies need 1/2 of a cup of sugar, how much sugar do 12 pies need? Multiply or divide to find the scale factor. Since 12 pies ÷ 2 pies = 6, the scale factor is 6, and 12 pies need 6 x 1/2 cup = 3 cups of sugar.
