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6-3 Estimating with Percents Warm Up Warm Up Lesson Presentation Lesson Presentation Problem of the Day Problem of the Day Lesson Quizzes Lesson Quizzes
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6-3 Estimating with Percents Warm Up Write each percent as a fraction and as a decimal. 1. 75% 2. 10% 3. 32% 4. 17% 3434, 0.75, 0.1 10 1, 0.32 25 8, 0.17 100 17
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6-3 Estimating with Percents Problem of the Day You are biking to the library. When you are 75% of the way there, you realize you forgot a book. So you turn around and head back. When you are of the way back you realize you don’t need the book, so you turn around again and bike 3.2 miles back to the library. How far do you live from the library? 6.4 miles 1313
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6-3 Estimating with Percents Prep for MA.7.A.1.2 Solve percent problems, including problems involving discounts, … taxes,…[and] tips… Sunshine State Standards
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6-3 Estimating with Percents The table shows common percents and their fraction equivalents. You can use fractions to estimate the percent of a number by choosing a fraction that is close to a given percent. Fraction Percent 10%20%25%50% 33 % 1313 66 % 2323 1515 1414 1313 1212 2323 1 10
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6-3 Estimating with Percents Use a fraction to estimate 27% of 63. Additional Example 1: Using Fractions to Estimate Percents 27% of 63 1414 · 63 1414 · 60 15 27% of 63 is about 15. Compatible numbers are close to the numbers in the problem and help you use mental math to find a solution. Remember! Think: 27% is about 25% and 25% is equivalent to. 1414 Change 63 to a compatible number. Multiply.
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6-3 Estimating with Percents Use a fraction to estimate 48% of 91. Check It Out: Example 1 48% of 91 1212 · 91 1212 · 90 45 48% of 91 is about 45. Think: 48% is about 50% and 50% is equivalent to. 1212 Change 91 to a compatible number. Multiply.
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6-3 Estimating with Percents Tara’s T’s is offering 2 T-shirts for $18, while Good-T’s is having a sale in which you buy one T-shirt for $9.99 and get 30% off a second T-shirt. Which store offers the better deal? Additional Example 2: Consumer Math Application First find the discount price for 2 t-shirts at Good T’s. 30% of $9.99 = 3 10 · $9.99 1313 $3.33 The second shirt costs approximately $3.33. Since $10 + $3 = $13, the 2 T-shirts at Good-T’s is the better deal. Think: 30% is equivalent to. 3 10 Change 3/10 to a compatible number. Multiply.
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6-3 Estimating with Percents Check It Out: Example 2 First find the discount on the notebook at Billy’s Office Supply. 25% of $9.75 = 1414 · $9.75 1414 · $10 $2.50 The discount is approximately $2.50. Since $10 - $2.50 = $7.50, the notebook from K’s Office Supply Store is the better deal. Think: 25% is equivalent to. 1 4 Change $9.75 to a compatible number. Multiply. Billy’s Office Supply Store is offering 25% off a leather notebook, originally priced at $9.75. K’s Office Supply Store offers the same notebook, not on sale, at $7.00. Which store offers the better deal?
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6-3 Estimating with Percents Another way to estimate percents is to find 1% or 10% of a number. You can do this by moving the decimal point in the number. 1% of 45 = 10% of 45 = To find 1% of a number, move the decimal point two places to the left. To find 10% of a number, move the decimal point one place to the left... 45..
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6-3 Estimating with Percents Use 1% or 10% to estimate the percent of each number. Additional Example 3A: Estimating with Simple Percents 4% of 18 18 is about 20, so find 4% of 20. 1% of 20 = 20. 4% of 20 = 4 · 0.2 = 0.8 4% of 18 is about 0.8. 4% equals 4 · 1%..
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6-3 Estimating with Percents Use 1% or 10% to estimate the percent of each number. Additional Example 3B: Estimating with Simple Percents 29% of 80 29% is about 30, so find 30% of 80. 10% of 80 = 80. 30% of 80 = 3 · 8.0 = 24.0 29% of 80 is about 24. 30% equals 3 · 10%..
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6-3 Estimating with Percents Use 1% or 10% to estimate the percent of each number. Check It Out: Example 3A 5% of 14 14 is about 15, so find 5% of 15. 1% of 15 = 15. 5% of 15 = 5 · 0.15 = 0.75 5% of 14 is about 0.75. 5% equals 5 · 1%..
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6-3 Estimating with Percents Use 1% or 10% to estimate the percent of each number. Check It Out: Example 3B 21% of 60 21% is about 20, so find 20% of 60. 10% of 60 = 60. 20% of 60 = 2 · 6.0 = 12.0 21% of 60 is about 12. 20% equals 2 · 10%..
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6-3 Estimating with Percents Tim spent $58 on dinner for his family. About how much money should he leave for a 15% tip? Additional Example 4: Consumer Math Application Since $58 is about $60, find 15% of $60. 15% = 10% + 5% 10% of $60 = $6 5% of $60 = $6 ÷ 2 = $3 $6 + $3 = $9 Tim should leave about $9 for a 15% tip. Think: 15% is 10% + 5%. 5% is of 10% so divide $6 by 2. 1212 Add the 10% and 5% estimates.
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6-3 Estimating with Percents Amanda spent $12 on a hair cut. About how much money should she leave for a 15% tip? Check It Out: Example 4 Since $12 is about $10, find 15% of $10. 15% = 10% + 5% 10% of $10 = $1 5% of $10 = $1 ÷ 2 = $0.50 $1 + $0.50 = $1.50 Amanda should leave about $1.50 for a 15% tip. Think: 15% is 10% + 5%. 5% is of 10% so divide $1 by 2. 1212 Add the 10% and 5% estimates.
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6-3 Estimating with Percents Standard Lesson Quiz Lesson Quizzes Lesson Quiz for Student Response Systems
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6-3 Estimating with Percents Lesson Quiz 1. Use a fraction to estimate 48% of 72. 2. A café is offering 10% off the $4.99 lunch. If a diner is offering the same lunch for $4.59, which is offering the better deal? Use 1% or 10% to estimate the percent of each number. 3. 4% of 220 4. 19% of 75 5. Mr. and Mrs. Dargen spend $46.25 on a meal. About how much should they leave for a 15% tip? the café 36 8.8 15 $7 Possible answers:
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6-3 Estimating with Percents 1. Use a fraction to estimate 52% of 84. A. 30 B. 40 C. 50 D. 60 Lesson Quiz for Student Response Systems
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6-3 Estimating with Percents 2. During the annual sale, Brand A offers 20% off on a $6.55 shirt. Which of the following will make Brand B a better deal? A. Brand B sells the same shirt for $4.89. B. Brand B sells the same shirt for $5.59. C. Brand B sells the same shirt for $5.89. D. Brand B sells the same shirt for $6.29. Lesson Quiz for Student Response Systems
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6-3 Estimating with Percents 3. Use 1% or 10% to estimate 6% of 239. A. 2.4 B. 14.4 C. 16.6 D. 24 Lesson Quiz for Student Response Systems
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6-3 Estimating with Percents 4. Use 1% or 10% to estimate 18% of 88. A. 8.8 B. 14 C. 18 D. 22 Lesson Quiz for Student Response Systems
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6-3 Estimating with Percents 5. Patricia bought accessories worth $52.75 in an online store. About how much would she spend for a 13% shipping charge? A. $5 B. $7 C. $9 D. $13 Lesson Quiz for Student Response Systems
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