1. Chapter 5: Division and Proportion in Algebra Lesson 5: Ratios

2. Vocabulary Ratios Ratios – are _______________________________ of ____________ quantities with the ________________ type of units. (example: length of side a of a square compared to the length of side b of another square would be ) Ratios can be written as ______________, ____________ or ________________. Ratios are most commonly written as _______________. comparisons sametwo fractionsdecimals percents fractions

3. Vocabulary Tax rate - is the __________of the tax amount to the selling price. ( ) Discount rate – is the _________of the discount amount to the original price. ( ) ratio

4. Example 2: It takes Mrs. Sweet hour to get to school each day. It takes her daughter only 10 minutes to get to her school where she also teaches Math. Find the ratio comparing the daughter’s time to Mrs. Sweet’s time.

5. Ratios and Percents Example 3: A TV that normally sells for $400 is on sale for $340. The tax on the sale price is $23.80, so the total cost with tax is $363.80. a) Find the discount rate. b)Find the tax rate. c) Including tax, how much would a customer save by buying the TV on sale?

6. Using Ratios to Set Up Equations Example 4: Instructions for preparing a lemonade drink call for 3 parts of water for each part of lemonade concentrate. How much of each ingredient is needed to make 10 gallons of lemonade?

7. Example 5: Susan is painting her bedroom wall pink. To get the desired pink color, she must mix 1 part red paint with 3 parts of white. How much white paint and red paint is needed to make 5 gallons of the pink paint?

8. Changing Ratios If the numerator or denominator changes in a ratio, then the ratio changes as well. For instance, Ben is 6 years old and his little sister Ella is 2. The ratio of Ben’s age to Ella’s age is. Ben is 3 times as old as Ella. In two years, the ratio changes to. Now Ben is only 2 times as old.

9. Example 6: Suppose a team has won 15 of its first 38 games. How many games must it win in a row to bring its winning percentage to at least 0.500?

10. 5-Minute Check What is a ratio? How is it different from a rate? How do you find the percent discount? How do you find the percent tax? Tell whether the fractions equal the ratio of 4 to 3.