Copyright © 2014, 2010, 2007 Pearson Education, Inc. Slide 1 Percent 7

Copyright © 2014, 2010, 2007 Pearson Education, Inc. Slide 2 R.1 Fractions 1.Estimate answers to percent problems involving 25%. 2.Find 10% and 1% of a number by moving the decimal point. 3.Solve basic percent problems using the percent equation. Objectives 7.3 The Percent Equation

Copyright © 2014, 2010, 2007 Pearson Education, Inc. Slide 3 Estimate answers to percent problems involving 25%. 25% means 25 parts out of 100 parts, or which is the same as. A quick way to find of a number is to divide it by 4. 25% of $40 would be of $40, or $10 The denominator, 4, tells you that the whole is divided into 4 equal parts.

Copyright © 2014, 2010, 2007 Pearson Education, Inc. Slide 4 Estimate answers to percent problems involving 25%. Example Estimate the answer to each question. (a)What is 25% of $817? Use front end rounding to round $817 to $800. Then divide $800 by 4. The estimate is $200. (b)Find 25% of 19.7 miles. Use front end rounding to round miles to 20 miles. Then divide 20 miles by 4. The estimate is 5 miles.

Copyright © 2014, 2010, 2007 Pearson Education, Inc. Slide 5 Find 10% and 1% of a number by moving the decimal point. Ten percent, or 10%, means 10 parts out of 100 parts or which is the same as A quick way to find of a number is to divide it by 10. The denominator, 10, tells you that the whole is divided into 10 equal parts. The shortcut for dividing by 10 is to move the decimal point one place to the left.

Copyright © 2014, 2010, 2007 Pearson Education, Inc. Slide 6 Example Find the exact answer to each question by moving the decimal point. (a)What is 10% of $817? (b)Find 10% of 19.7 miles. Find 10% and 1% of a number by moving the decimal point.

Copyright © 2014, 2010, 2007 Pearson Education, Inc. Slide 7 Find 10% and 1% of a number by moving the decimal point. One percent, or 1%, means 1 part out of 100 parts or The denominator, 100, tells you that the whole is divided into 100 equal parts. The shortcut for dividing by 100 is to move the decimal point two place to the left.

Copyright © 2014, 2010, 2007 Pearson Education, Inc. Slide 8 Example Find the exact answer to each question by moving the decimal point. (a)What is 1% of $817? (b)Find 1% of 19.7 miles. Find 10% and 1% of a number by moving the decimal point.

Copyright © 2014, 2010, 2007 Pearson Education, Inc. Slide 9 Find 10% and 1% of a number by moving the decimal point.

Copyright © 2014, 2010, 2007 Pearson Education, Inc. Slide 10 Solve basic percent problems using the percent equation.

Copyright © 2014, 2010, 2007 Pearson Education, Inc. Slide 11 Solve basic percent problems using the percent equation. Example 15% of $165 is how much money? Check 10% of $165 is $16.50 and 5% is half that or about $8. So 15% is approximately $ $8 = $ The solution seems reasonable.

Copyright © 2014, 2010, 2007 Pearson Education, Inc. Slide 12 Solve basic percent problems using the percent equation. Example Check The solution seems reasonable since 80 is close to 84. How many students is 210% of 40 students?

Copyright © 2014, 2010, 2007 Pearson Education, Inc. Slide 13 Solve basic percent problems using the percent equation. Example 8 pounds is what percent of 160 pounds? Check 10% of 160 pounds is 16 pounds. 5% is half that or 8 pounds. The solution is correct.

Copyright © 2014, 2010, 2007 Pearson Education, Inc. Slide 14 Solve basic percent problems using the percent equation. Example What percent of $50 is $68? Check 100% of $50 is $ % of $50 is $ % is between 100% and 200% and $68 is between $50 and $100. The solution seems reasonable.

Copyright © 2014, 2010, 2007 Pearson Education, Inc. Slide 15 Solve basic percent problems using the percent equation. Example 162 credits is 90% of how many credits? Check 100% of 180 is % of 180 is % of 180 is 180 – 18 = 162. The solution is correct.

Copyright © 2014, 2010, 2007 Pearson Education, Inc. Slide 16 Solve basic percent problems using the percent equation. Example 250% of what amount is $75? Check 200% of $30 is $60. 50% of $30 is $ % of $30 is $60 + $15 = $75. The solution is correct.