R ATIOS AND P ROPORTIONS Objective: Finding Equivalent Ratios to Create Proportions.

R ATIO What is a Ratio? A ratio is a comparison of two quantities(numbers) using division Three Ways to Write a Ratio FractionWith “to”With “:”

T RY T HIS ! What is the ratio of shaded squares to unshaded squares? box 1 box 2 These 2 ratios are called equivalent ratios GCF of 20 and 28

E QUIVALENT R ATIOS What are Equivalent Ratios? Equivalent ratios are ratios that make the same comparison Examples: Multiply by any number These equivalent ratios are proportional.

P ROPORTIONAL What is a Proportional or in Proportion? Proportions are equivalent ratios that are identical when in simplest form. Examples:

T RY T HESE !

A PPLICATION At 4  C, two cubic feet (ft 3 ) of silver has the same mass as 21 ft 3 of water. At 4  C, would 126 ft 3 of water have the same mass as 6 ft 3 of silver? Already reduced

E XAMPLE 1: A recipe calls for 1.5 cups of pancake mix to make 8 pancakes. Josh wans to make 12 pancakes with2 cups of mix. Does Josh have the correct ratio for the recipe? Explain.

E XAMPLE 2: Find two ratios that are equivalent to each given ratio. A.. B..

E XAMPLE 3: Tell whether the ratios form a proportion. If not, find a ratio that would form a proportion with each ratio. A.. B..