6.3 Students will be able to use estimates to solve percent problems. Warm Up 1.What is 23% of 24? 2.What number is 85% of 103? 3.What percent of 23 is 9? 4.42% of what number is 28? 5.Solve for x. 5x = 24 6.I went out to eat and spent $ How much did I spend in tip if the service was excellent? How much would the whole meal cost? % 66.7 X = 4.8 $4.00 or $5.00 $28.38 or $29.38

6.3 Students will be able to use estimates to solve percent problems. An estimate is a useful answer that is close to the exact answer.

6.3 Students will be able to use estimates to solve percent problems. Daily Quiz Green 1.I went out to eat and spent How much would I spend on tip if the service was excellent? Blue 1.I went out to eat and spent $ How much would I spend on the whole meal (including tip), if the service was good. Red 1. I went out to eat and spent How much would I spend on the whole meal (including tip), if the service was poor. $6.00 $75.48 $33.73

6.3 Students will be able to use estimates to solve percent problems. Benchmark: 10% (Estimate) What is 10% of 20? What is 10% of 30? What is 10% of 89.83? What is 10% of 59.28? What is 10% of 28.39? What is 30% of 25? What is 30% of 35? What is 30% of 89.83? What is 30% of 59.28? What is 30% of 28.39? Benchmark: 30%

6.3 Students will be able to use estimates to solve percent problems. Estimate. 21% of 66 Estimating with Percents 21% ≈ 20%Use a benchmark close to 21%. 66 ≈ 65 Use compatible numbers. So 21% of 66 is about % of 65 = 6.5 Use the benchmark percents to find 10% 20% of 65 = 13 Double to find 20%

6.3 Students will be able to use estimates to solve percent problems. Estimate. 29% of 86 Try It 29% ≈ 30%Use a benchmark close to 29%. 86 ≈ 90 Use compatible numbers 10% of 90 = 9 Find 10% So 29% of 86 is about % of 90 = 9(3) = 27 Multiply 10% by 3

6.3 Students will be able to use estimates to solve percent problems. Estimate. 36% of 120 Estimating with Percents Instead of computing the exact answer of 36%  120, estimate. 36%  35%Round.  30% + 5% Break down the percent into smaller parts.  12 Find 10%  36 Multiply by 3 to get 30% Divide 10% by 2 to get 5%  = 42 Add 30% and 5%

6.3 Students will be able to use estimates to solve percent problems. Estimate. 44% of 131 Estimating with Percents Instead of computing the exact answer of 44%  141, estimate. 44%  45%Round.  40% + 5% Break down the percent into smaller parts.  14 Find 10%  42 Multiply by 3 to get 30% Divide 10% by 2 to get 5%  = 49 Add 30% and 5%

6.3 Students will be able to use estimates to solve percent problems. What percent is: 1 out of 2 50% 3 out of 4 75% 80 out of % 13 out of % 400 out of % 5 out of 500 1%

6.3 Students will be able to use estimates to solve percent problems. Estimate each percent 1.82 out of out of out of out of out of % 75% 50% 30% 100%

6.3 Students will be able to use estimates to solve percent problems. Try It A clothing company has determined that approximately 9% of the sheets it makes are irregular. Out of a shipment of 4073, the company manager estimates that 397 sheets are irregular. Estimate to see if the manager’s number is reasonable. Explain. 9%  4073 ≈ 10%  4000Use compatible numbers. ≈ 0.10  4000Write 10% as a decimal. Multiply. ≈ 400 Because 397 is close to 400, the manager’s number is reasonable.

6.3 Students will be able to use estimates to solve percent problems. Lesson Quiz: Part I Estimate % of % of Ian had dinner with some friends at a restaurant. His food and drink cost $ If the sales tax is 8.25% and he wants to leave a 20% tip, about how much should Ian pay? 4 90 $13.00 Possible answers:

6.3 Students will be able to use estimates to solve percent problems. Lesson Quiz: Part II 4. Approximately 8% of each batch of jeans produced at one factory is defective. Ms. Fleming said that in a batch of 400 jeans, about 35 jeans would be defective. Estimate to determine if her number is reasonable. Explain. Yes, it is reasonable because 8% of 400 is a little less than 10% of % of 400 is 40, and 35 is a little less than 40.

6.3 Students will be able to use estimates to solve percent problems. 1. Estimate. 26% of 35 A. 8 B. 9 C. 17 D. 26 Lesson Quiz for Student Response Systems

6.3 Students will be able to use estimates to solve percent problems. 2. Smith bought a book at an online store. The cost of the book was $ If the sales tax rate is 7.75% and the shipping charges are 10% of the cost of the book, about how much should he pay? A. $13.14 B. $14.42 C. $15.25 D. $16.50 Lesson Quiz for Student Response Systems

6.3 Students will be able to use estimates to solve percent problems. 3. On an average 9% of the CDs produced by a company are defective. The Quality Control Manager states that out of 1300 CDs produced, 121 are defective. Estimate to determine if his number is reasonable. Explain. A. yes; because 9% of 1300 is a little less than 10% of % of 1300 is 130 and 121 is a little less than 130. B. no: because 9% of 1300 is a little greater than 10% of % of 1300 is 130 which is greater than 121. Lesson Quiz for Student Response Systems