1. Course 2, Lesson 2-5 Use the determine reasonable answers strategy to solve Exercises 1–4. 1. If the speed limit is 65 miles per hour, what is a reasonable amount of time for the Blackwells to travel 300 miles? 2. There are 400 boys at Oak Middle School and 12% play football. What is a reasonable number of boys that play football? 3. Suppose you are going to dinner and a movie with a friend. If you spend $18 and the movie is 62% of the cost, what is a reasonable cost for dinner? 4. Lisa has 6 coins that total $0.86. What are the coins? 5. A number is multiplied by 13. Then 5 is subtracted from the product. The result is 60. What is the number?

2. Course 2, Lesson 2-5 ANSWERS 1. 5 hours 2. 50 3. $7.00 4. 3 quarters, 2 nickels, 1 penny 5. 5

3. HOW can percent help you understand situations involving money? Ratios and Proportional Relationships Course 2, Lesson 2-5

4. Ratios and Proportional Relationships Course 2, Lesson 2-5 Common Core State Standards © Copyright 2010. National Governors Association Center for Best Practices and Council of Chief State School Officers. All rights reserved. 7.RP.3 Use proportional relationships to solve multistep ratio and percent problems. 7.EE.3 Solve multistep real-life and mathematical problems posed with positive and negative rational numbers in any form (whole numbers, fractions, and decimals), using tools strategically. Apply properties of operations to calculate with numbers in any form; convert between forms as appropriate; and assess the reasonableness of answers using mental computation and estimation strategies.

5. Ratios and Proportional Relationships Course 2, Lesson 2-5 Common Core State Standards © Copyright 2010. National Governors Association Center for Best Practices and Council of Chief State School Officers. All rights reserved. Mathematical Practices 1Make sense of problems and persevere in solving them. 3Construct viable arguments and critique the reasoning of others. 4Model with mathematics. 5Use appropriate tools strategically. 6Attend to precision.

6. Find percent of change Find percent error Ratios and Proportional Relationships Course 2, Lesson 2-5

7. Ratios and Proportional Relationships Course 2, Lesson 2-5 percent of change percent of increase percent of decrease percent error

8. Ratios and Proportional Relationships Course 2, Lesson 2-5 Words A percent of change is a ratio that compares the change in quantity to the original amount. Equation percent of change =

9. Ratios and Proportional Relationships Course 2, Lesson 2-5 Words The is a ratio that compares the inaccuracy of an estimate, or amount of error, to the actual amount. Equation percent error = percent error

10. How did what you learned today help you answer the HOW can percent help you understand situations involving money? Course 2, Lesson 2-5 Ratios and Proportional Relationships

11. How did what you learned today help you answer the HOW can percent help you understand situations involving money? Course 2, Lesson 2-5 Ratios and Proportional Relationships Sample answers: You can find the percent of change in the in a real- world situation involving money. You can find the percent error in the estimated cost of an item compared to the actual cost.

12. The next lesson involves solving problems involving sales tax, tips, and markup. How do you think what you learned today will connect with the next lesson? Ratios and Proportional Relationships Course 2, Lesson 2-5