# Ratios & Proportions

Created 3 years ago

Duration 0:12:46
194
Slide Content
1. ### Slide 1 - Ratios & Proportions

• Solving Proportions with algebra

3. ### Slide 3 - A ratio compares two quantities

• Brownie Recipe
• 1⁄2 cup vegetable oil
• 1 cup sugar
• 1 teaspoon vanilla
• 2 large eggs
• 1⁄4 teaspoon baking powder
• 1⁄3 cup cocoa powder
• 1⁄4 teaspoon salt
• 2 cup flour
• What is the ratio of flour to sugar?
4. ### Slide 4 - Brownie Recipe

• 1⁄2 cup vegetable oil
• 1 cup sugar
• 1 teaspoon vanilla
• 2 large eggs
• 1⁄4 teaspoon baking powder
• 1⁄3 cup cocoa powder
• 1⁄4 teaspoon salt
• 2 cup flour
5. ### Slide 5 - When we scale up a ratio, it creates an equivalent ratio

• Single Brownie Recipe
• 1⁄2 cup vegetable oil
• 1 cup sugar
• 1 teaspoon vanilla
• 2 large eggs
• 1⁄4 teaspoon baking powder
• 1⁄3 cup cocoa powder
• 1⁄4 teaspoon salt
• 2 cup flour
• Double Brownie Recipe
• 1 cup vegetable oil
• 2 cup sugar
• 2 teaspoon vanilla
• 4 large eggs
• 1⁄2 teaspoon baking powder
• 2⁄3 cup cocoa powder
• 1⁄2 teaspoon salt
• 4 cup flour
• X 2 =
6. ### Slide 7 - A unit rate can be useful when comparing two ratios

• To find the unit rate, write the two quantities as a ratio and simplify so that the denominator is one. [Divide the top by the bottom].
• A 5lb bag of flour is \$2.29. A 12lb bag of flour is \$5.90. Which bag has a lower price per pound?

9. ### Slide 11 - Two equivalent ratios can be written as a proportion

• Single Brownie Recipe
• 1 cup sugar
• 2 cup flour
• Double Brownie Recipe
• 2 cup sugar
• 4 cup flour
• X 2 =
10. ### Slide 13 - A proportion can be solved using mental math

• Single Brownie Recipe
• 1⁄2 cup vegetable oil
• 1 cup sugar
• 1 teaspoon vanilla
• 2 large eggs
• 1⁄4 teaspoon baking powder
• 1⁄3 cup cocoa powder
• 1⁄4 teaspoon salt
• 2 cup flour
• If we scaled this recipe up to make three servings, how much sugar would you need when using 6 cups of flour?
11. ### Slide 15 - A proportion can be solved using Algebra

• To solve a proportion using algebra, take the cross-product and simplify.