Use with Lesson 5MAFS.7.RP.1.3

Course 2, Lesson 2-5Mathematics Florida Standards – Mathematics, numbering and wording from www.cpalms.org.

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?

ANSWERS

1. 5 hours

2. 50

3. $7.00

4. 3 quarters, 2 nickels, 1 penny

5. 5

Course 2, Lesson 2-5Mathematics Florida Standards – Mathematics, numbering and wording from www.cpalms.org.

Use with Lesson 5MAFS.7.RP.1.3

HOW can percent help you understand situations involving money?

Course 2, Lesson 2-5

• MAFS.7.RP.1.3 Use proportional relationships to solve multistep ratio and percent problems.

• MAFS.7.EE.2.3 Solve multi-step 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.

Mathematical PracticesMP1 Make sense of problems and persevere in solving them.

MP3 Construct viable arguments and critique the reasoning of others.

MP4 Model with mathematics.

MP5 Use appropriate tools strategically.

MP6 Attend to precision.Course 2, Lesson 2-5Mathematics Florida Standards – Mathematics, numbering and wording from www.cpalms.org.

To• find percent of change• find percent error

Course 2, Lesson 2-5

• percent of change• percent of increase• percent of decrease• percent error

Course 2, Lesson 2-5

Percent of Change

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 =amount of change

original amount

Percent Error

Course 2, Lesson 2-5

Words The percent error is a ratio that compares the inaccuracy of an estimate, or amount of error, tothe actual amount.

Equation percent error =amount of error

actual amount

HOW can percent help you understand situations involving money?

Course 2, Lesson 2-5

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.

Course 2, Lesson 2-5

HOW can percent help you understand situations involving money?

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?

Course 2, Lesson 2-5