1. Objective SWBAT estimate percents SWBAT estimate percents

2. “Estimating with Percents” You can use fractions or decimals to estimate with percents. You can use fractions or decimals to estimate with percents.

3. Estimating Percents with Fractions Percent10%20%25% 33 % 50% 50% 66 % Fraction You can estimate the percent of a number by substituting a fraction that is close to a given percent. A basketball costs $14.99 at Modell’s. Sports Authority is offering the same basketball at 20% off the regular price of $19.99. Estimate to determine which store is offering the better deal? A basketball costs $14.99 at Modell’s. Sports Authority is offering the same basketball at 20% off the regular price of $19.99. Estimate to determine which store is offering the better deal? Find 20% of $19.99 Compatible numbers – numbers that are close and help you use mental math to find the solution

4. Use a fraction and compatible numbers to estimate the percent of each number. means multiplication 25% 1 4 Find 25% of 35. 34% 1 3 Find 34% of 63. Finding Percent of a Number 8% 110 Find 8% of 261.

5. Estimating Percents with Decimals 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% Find of any number by moving the decimal point 2 places to the left. 10% Find of any number by moving the decimal point 1 place to the left. Find 1% of 45 45 = 0.45.0 Find 10% of 45 45 = 4.5.0

6. Use 1% or 10% to estimate the percent of each number. Find 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%.. Find 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%..

7. Real-Life Application Tim spent $58 on dinner for his family. About how much money should he leave for a 15% tip? 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.

8. Real-Life Application Amanda spent $12 on a hair cut. About how much money should she leave for a 15% tip? 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.