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Unit Rates Lesson 6.2
CCS: 6.RP.2. Understand the concept of a unit rate a/b associated with a ratio a:b with b ≠ 0, and use rate language in the context of a ratio relationship.6.RP.3. Use ratio and rate reasoning to solve real-world and mathematical problems, e.g., by reasoning about tables of equivalent ratios, tape diagrams, double number line diagrams, or equations Objectives: • Students will find rates and unit rates • Students will compare unit prices • Students will solve real world problems using unit rates
Check the Skills You’ll Need A drama club has 14 females and 8 males. Write each ratio in three ways: • Males to females • Females to males • Total to females Write each ratio in simplest form: • 8 to 12 • 10:6 8 to 14, 8:14. 8/14 14 to 8, 14:8. 14/8 22 to 14, 22:14, 22/14 2 to 3 5:3
Vocabulary • Arateis a ratio that compares two quantities measured in different units. • The unit rateis the rate for one unit of a given quantity. Unit rates have a denominator of 1. • A unit price is a unit rate that gives the cost per unit
Examples Rate: 150 heartbeats 2 minutes Unit Rate (Divide to get it): 150 ÷ 2 = 75 heartbeats per minute.
Find the Unit Rate Amy can read 88 pages in 4 hours. What is the unit rate? (How many pages can she read per hour?) 88 pages 22 pages / hour 4 hours
Using Unit Rates • You can find the missing terms of equal ratios. • Use the unit rate, and set it equal to another ratio. • Solve for what is missing by dividing or multiplying.
Example Joe’s car goes 25 miles per gallon of gasoline. How far can it go on 8 gallons of gasoline? x 8 25 miles = Unit Rate 8 gallons 1 gallon x 8 25 x 8 = 200. Joe’s car can go 200 miles on 8 gallons of gas.
Comparing Unit Prices • Use division to find the unit prices of the two products in question. • The unit rate that is smaller (costs less) is the better value.
Example Juice is sold in two different sizes. A 48-fluid ounce bottle costs $2.07. A 32-fluid ounce bottle costs $1.64. Which is the better buy? $2.07 $0.04 per fl.oz. 0.043125 48 fl.oz. $1.64 $0.05 per fl.oz. 0.05125 32 fl.oz. The 48 fl.oz. bottle is the better value.
Classwork: Play this Jeopardy style game with a partner to practice rates and unit rates. Then…Check out this interactive for ratios and unit rates. You can click on lessons, interactives, or applications.Try it at BRAINCAMPHomework Time:pg. 275, 2-38 Even