1 / 18

Finding Percents

Finding Percents. 8.2. Pre-Algebra. 24. 50. 4. 1. 25. 4. 3. 8. Warm Up. Rewrite each value as indicated. 1. as a percent 2. 25% as a fraction 3. as a decimal 4. 0.16 as a fraction. 48%. 0.375. Learn to find percents. 88. p =. Solve for p. 220.

bruno-stokes
Download Presentation

Finding Percents

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Finding Percents 8.2 Pre-Algebra

  2. 24 50 4 1 25 4 3 8 Warm Up • Rewrite each value as indicated. • 1. as a percent • 2. 25% as a fraction • 3. as a decimal • 4. 0.16 as a fraction 48% 0.375

  3. Learn to find percents.

  4. 88 p = Solve for p. 220 Example: Finding the Percent One Number Is of Another A. What percent of 220 is 88? Method 1: Set up an equation to find the percent. p 220 = 88 Set up an equation. p= 0.4 0.4 is 40%. So 88 is 40% of 220.

  5. number part 100 = whole 24 n = 160 100 Example: Finding the Percent One Number Is of Another B. Eddie weighs 160 lb, and his bones weigh 24 lb. Find the percent of his weight that his bones are. Think:What number is to 100 as 24 is to 160? Set up a proportion. Substitute. n 160 = 100 24 Find the cross products. 160n = 2400

  6. 2400 n = 160 15 24 = 100 160 Example Continued Solve for n. n = 15 The proportion is reasonable. So 15% of Eddie’s weight is bone.

  7. 11 p = Solve for p. 110 Try This A. What percent of 110 is 11? Method 1: Set up an equation to find the percent. p110 = 11 Set up an equation. p= 0.1 0.1 is 10%. So 11 is 10% of 110.

  8. number part 100 = whole 21 n = 140 100 Try This B. Jamie weighs 140 lb, and his bones weigh 21 lb. Find the percent of his weight that his bones are. Think:What number is to 100 as 21 is to 140? Set up a proportion. Substitute. n 140 = 100 21 Find the cross products. 140n = 2100

  9. 2100 n = 140 15 21 = 100 140 Example Continued Solve for n. n = 15 The proportion is reasonable. So 15% of Jamie’s weight is bone.

  10. A. After a drought, a reservoir had only 66 % of the average amount of water. If the average amount of water is 57,000,000 gallons, how much water was in the reservoir after the drought? 2 2 2 2 3 3 3 3 Think:What number is 66 % of 57,000,000? w = 66 % 57,000,000 Set up an equation. w = 57,000,000 66 % is equivalent to . 2 2 3 3 Example: Finding a Percent of a Number Choose a method: Set up an equation.

  11. 114,000,000 3 w = = 38,000,000 Example Continued The reservoir contained 38,000,000 gallons of water after the drought.

  12. Set up a proportion. = 110 a 100 550 Example: Finding Percents B. Ms. Chang deposited $550 in the bank. Four years later her account held 110% of the original amount. How much money did Ms. Chang have in the bank at the end of the four years? Choose a method: Set up a proportion. 110  550 = 100 a Find the cross products. 60,500 = 100a

  13. Example Continued 605 = a Solve for a. Ms. Chang had $605 in the bank at the end of the four years.

  14. A. After a drought, a river had only 50 % of the average amount of water flow. If the average amount of water flow is 60,000,000 gallons per day, how much water was flowing in the river after the drought? 2 2 2 3 3 3 Think:What number is 50 % of 60,000,000? w = 50 % 60,000,000 Set up an equation. 2 3 w = 0.506 60,000,000 50 % is equivalent to 0.506. Try This Choose a method: Set up an equation.

  15. Try This w = 30,400,000 The water flow in the river was 30,400,000 gallons per day after the drought.

  16. Set up a proportion. = 120 a 100 770 Try This B. Mr. Downing deposited $770 in the bank. Four years later her account held 120% of the original amount. How much money did Mr. Downing have in the bank at the end of the four years? Choose a method: Set up a proportion. 120 770 = 100 a Find the cross products. 92,400 = 100a

  17. Try This 924 = a Solve for a. Mr. Downing had $924 in the bank at the end of the four years.

  18. Lesson Quiz Find each percent to the nearest tenth. 1. What percent of 33 is 22? 2. What percent of 300 is 120? 3. 18 is what percent of 25? 4. The volume of Lake Superior is 2900 mi3 and the volume of Lake Erie is 116 mi3. What percent of the volume of Lake Superior is the volume of Lake Erie? 66.7% 40% 72% 4%

More Related