Lesson 10 Estimation Grade 7 Week #5

1. Lesson 10 Estimation Grade 7 Week #5 Founders’ Hall Math - PSSA

2. Round decimals and fractions and then compute with the rounded numbers to estimate a solution. • $51,950 rounds to $52,000 • Round to the greatest place. • 18.9 rounds to 20 • 11.05 rounds to 10 • Round each fraction to the nearest whole number. • rounds to 5 • 9 rounds to 9 7 8 1 5

3. Check it out with the Coach Your friend says that 598.034 – 189.95 = 308.084. Is your friend’s answer correct? 598.034 rounded to its greatest place is 600 189.95 rounded to its greatest place is 200 So, a good estimate of 598.034 – 189.95 is: 600 – 200 = 400 Your friend’s answer is incorrect because the estimated difference is 100 to your friend’s answer.

4. Sample Test Questions 1. Chandra bought 3 T-shirts that cost $10.95 each, and 2 caps that cost $9.95 each. Which of the following is the best estimate of her total purchase? A $50 B $60 C $70 D $80 Answer A $50

5. Darlene earns $4,128 per month. She works 21 days per month. Which of the following is the best estimate of the amount she earns per day? • A $150 • B $200 • C $250 • D $300 • Answer B $200

6. A rectangular lot measures 49.85 m long and 21.6 m wide. Which of the following is the best estimate of the area of the lot? • A 100 sq in • B 800 sq in • C 1,000 sq in • D 8,000 sq in • Answer C 1,000 sq in

7. Use estimation to determine the most reasonable quotient for 46.28 / 2.6. • A 0.178 • B 1.78 • C 17.8 • D 178 • Answer C 17.8

8. 7 8 • Maria painted 4 feet of wood trim on Thursday, 9 feet on Friday, and 15 feet on Saturday. Use estimation to determine which of the following is total number of feet of trim Maria painted. • A 18 feet • B 27 feet • C 29 feet • D 39 feet • Answer c 29 feet 1 5 1 10 7 20 7 20 7 40 7 40 7 40

9. The population of Philadelphia in the year 1900 was 1,293,697. In the year 2000, the population was 1,517,550. Which of the following is the best estimate of the increase in the population from 1900 to 2000? • A 100,000 • B 200,000 • C 300,000 • D 400,000 • Answer B 200,000

10. 11 16 • Jeannine is 67 inches tall. Her brother Nicholas is 59 inches tall. Which is the best estimate of how much taller Jeannine is? • A 13 inches • B 11 inches • C 9 inches • D 7 inches • Answer C 9 inches 1 8

11. Without doing the multiplication, which must be the product for 105.6 x 0.22? • A 0.232232 • B 2.32232 • C 23.232 • D 232.32 • Answer C 23.232

12. Without doing the multiplication, which must be the product for 2 x 7 ? A 9 B 12 C 18 D 21 Answer C 18 1 3 5 6 5 18 5 18 5 18 5 18 5 18

13. Patricia will make car payments of $314.99 per month for 4 years. Which of the following is the best estimate of the total amount she will pay after 4 years? • A $12,000 • B $15,000 • C $18,000 • D $21,000 • Answer B $15,000

14. 3 4 11. A. 3 rounds to 4 3 rounds to 3 4 x 3 = 12 My friend’s answer of 19 is incorrect. 12 is the correct estimate. 11. B. 2 9 15 4 29 9 435 36 1 12 x = 12 =

15. Progress Check For Lessons 1-10 9 20 • What is written as a percent? • A 18% • B 27% • C 45% • D 81% • Answer C 45%

16. Which shows these numbers ordered from least to greatest? • 4.012, 3 , 3.475, 3 • A 3.475, 3 , 3 , 4.012 • B 3.475, 3 , 3 , 4.012 • C. 3 , 3.475, 3 , 4.012 • D. 3 , 3 , 3.475, 4.012 • Answer A 5 8 12 15 12 15 5 8 5 8 12 15 12 15 5 8 5 8 12 15

17. Daisy records the temperature in her garden every morning at 6 A.M. Below are the temperatures from the last 3 days. • 2 ˚ F, -4˚ F, -1˚ F • Which of the following lists the temperatures in order from least to greatest • A -1˚, 2˚, -4˚ • B 2˚ , -1˚, -4˚ • C -4˚, -1˚, 2˚ • D -1˚, -4˚, 2˚ • Answer C -4˚, -1˚, 2˚

18. 4. Which point on the number line is closest to ? A B C D -1 0 1 2 A point A B point B C point C D point D Answer B point B

19. Jocee paid $92 to rent skis for 4 days. At this rate, how much does it cost to rent skis for one day? • A $20 • B $22 • C $23 • D $25 • Answer C $23

20. Robin and Julie picked apples on a farm. The ratio of the number of apples that Robin picked to the number of apples that Julie picked was 11:8. Together, they picked 114 apples. How many apples did Julie pick? • A 48 • B 52 • C 60 • D 66 • Answer A 48

21. Bridgette was making gift baskets for her friends. She put 7 pieces of candy in each basket. If she used 98 pieces of candy, how many gift baskets did Bridgette make? • A 11 • B 12 • C 13 • D 14 • Answer D 14

22. What is the value of this expression? • 96 – 3 (4² - 2³) x 4 • A 0 • B 18 • C 192 • D 2,976 • Answer A 0

23. There are 13 girls in Mrs. Jackson’s class of 22 students. Which ratio compares the number of boys to the number of students in the class? • A 13/22 • B 13/9 • C 9/13 • D 9/22 • Answer D 9/22

24. A radio station plays 3 songs in 12 minutes. If the station continues to play songs at the same rate, how many songs will it play in one hour? • A 12 • B 15 • C 18 • D 21 • Answer B 15

25. The restaurant bill for a group of friends came to $89.75. The friends want to leave a tip of 20%. Which of the following is the best estimate of how much they should leave as a tip? • A $9 • B $12 • C $18 • D $24 • Answer C $18