1 / 27

Finding Percents: Warm Up, Examples, and Applications

In this lesson, learn how to find percents and apply the concept to various problems. Warm up with rewriting values as percents, fractions, and decimals. Then, practice finding the percent one number is of another and solve real-world applications.

heffernan
Download Presentation

Finding Percents: Warm Up, Examples, and Applications

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. 6-3 Finding Percents Course 3 Warm Up Problem of the Day Lesson Presentation

  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. Problem of the Day A number between 1 and 10 is halved, and the result is squared. This gives an answer that is double the original number. What is the starting number? 8

  4. Learn to find percents.

  5. number part 100 = whole 66 n = 92 100 Additional Example 1A: Finding the Percent One Number Is of Another What percent of 92 is 66? Method 1: Set up a proportion to find the percent. Think:What number is to 100 as 66 is to 92? Set up a proportion. Substitute. n 92 = 100 66 Find the cross products. 92n = 6600

  6. 6600 n = 92 72 66 = 100 92 Additional Example 1A Continued Solve for n. n ≈ 72 The proportion is reasonable. 66 is approximately 72% of 92.

  7. = 88 220p 220 220 Additional Example 1B: Finding the Percent One Number Is of Another What percent of 220 is 88? Method 2: Set up an equation to find the percent. p 220 = 88 Set up an equation. Divide both sides by 220. p= 0.4 0.4 is 40%. So 88 is 40% of 220.

  8. ? 40%  220 = 88 Substitute 40% for p. ? 0.40  220 = 88 Write a decimal and multiply. Additional Example 1B Continued Check 88 = 88 40% of 220 is 88.

  9. number part 100 = whole 21 n = 140 100 Check It Out: Example 1A What percent of 140 is 21? Method 1: Set up a proportion to find the percent. 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

  10. 2100 n = 140 15 21 = 100 140 Check It Out: Example 1A Continued Solve for n. n = 15 The proportion is reasonable. 21 is 15% of 140.

  11. 11 p = Solve for p. 110 Check It Out: Example 1B What percent of 110 is 11? Method 2: 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.

  12. ? 10%  110 = 11 Substitute 10% for p. ? .10  110 = 11 Write a decimal and multiply Additional Example 1B Continued Check 11 = 11 10% of 110 is 11.

  13. 1 5 = 20% and 0.31 = 31%. Additional Example 2A: Recreation Application Four friends volunteered to cut the grass around their neighbor’s house. Jay cut 23% of the grass, Aimee cut of the grass, Ken cut 0.31 of the grass, and Bryn cut the rest. What percent of the grass did Bryn cut? 1 5 First, find what percent of the grass Aimee and Ken cut. Next, subtract the percents you know from 100% to find the remaining percent. 100% - 23% - 20% - 31% = 26%. Bryn cut 26% of the grass.

  14. 2 5 = 40% and 0.325 = 32.5% Additional Example 2B: Recreation Application Jeremy organizes his movie collection by genre. of his collection are dramas, 0.325 are action films, 3% are documentaries, 19.5% are comedies, and the rest of his movies are independent films. What percent of his movie collection are independent films? 2 5 First, find what percent of his films are dramas and action. Next, subtract the percents you know from 100% to find the remaining percent. 100% - 40% - 32.5% - 3% - 19.5% = 5%. 5% of Jeremy’s movie collection are independent films.

  15. 3 5 = 60% and 0.19 = 19%. Check It Out: Example 2A Four store employees stock the shelves at the Electronics Store. Francisco stocked 14% of the shelves, Lauren stocked of the shelves, Ling stocked 0.19 of the shelves, and Mark stocked the rest. What percent of the shelves did Mark stock? 3 5 First, find what percent of the shelves Lauren and Ling stocked. Next, subtract the percents you know from 100% to find the remaining percent. 100% - 14% - 60% - 19% = 7%. Mark stocked 7% of the shelves.

  16. 1 2 = 50% and 0.125 = 12.5% Check It Out: Example 2B Joe organizes his CD collection by genre. of his collection is rock, 0.125 is pop, 6% is classical, 9.5% is country, and the rest of his CDs are jazz. What percent of his CD collection is jazz? 1 2 First, find what percent of his CDs are rock and pop. Next, subtract the percents you know from 100% to find the remaining percent. 100% - 50% - 12.5% - 6% - 9.5% = 22%. 22% of Joe’s CD collection is jazz.

  17. 55 100 p = 1,189,000 Additional Example 3A: Finding the Percent of a Number The city of Dallas, Texas has a population of approximately 1,189,000 people. The population of the city of Austin, Texas is 55% of the population of Dallas. To the nearest thousand, what is the population of Austin? Choose a method: Set up a proportion. Think:55 is to 100 as what population is to 1,189,000. Set up a proportion. 55  1,189,000 = 100 pFind the cross products.

  18. 65,395,000 100 100 100 = Additional Example 3A Continued 65,395,000 = 100p Simplify. Divide both sides by 100. 653,950 = p Simplify. 654,000 ≈ p Round to the nearest whole number. Austin has a population of approximately 654,000.

  19. Helpful Hint When solving a problem with a percent greater than 100, look for the number that will be greater than the number given.

  20. 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 Additional Example 3B: Finding the Percent of a Number 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? Choose a method: Set up an equation.

  21. 114,000,000 3 Additional Example 3B Continued w = = 38,000,000 Simplify. The reservoir contained 38,000,000 gallons of water after the drought.

  22. 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. Check It Out: Example 3A 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? Choose a method: Set up an equation. w = 30,400,000 Simplify.

  23. Check It Out: Example 3A Continued The water flow in the river was 30,400,000 gallons per day after the drought.

  24. 35 100 s = 214,000 Check It Out: Example 3B Ms. Marvin has a savings account with approximately $214,000 in it. Mr. Parson has 35% of the amount of Ms. Marvin’s savings account. To the nearest thousand, what is the amount of Mr. Parson’s savings account? Choose a method: Set up a proportion. Think:35 is to 100 as what amount is to $214,000. Set up a proportion. 35  214,000 = 100 sFind the cross products.

  25. 7,490,000 100 100 100 = Check It Out: Example 3B Continued 7,490,000 = 100s Simplify. Divide both sides by 100. 74,900 = s Simplify. 75,000 ≈ s Round to the nearest whole number. Mr. Parson has approximately $75,000 in his savings account.

  26. 2 3 66 % Lesson Quiz: Part I Find each percent. 1. What percent of 33 is 22? 2. Of Earth’s 197 million mi2 of surface area, about 139 million mi2 is water. Find the percent of Earth’s surface that is covered by water. 3. The Ramirez family bought a large bag of oranges during their trip to Florida. Jorge ate of the oranges, Ann ate 0.18 of the oranges, Mrs. Ramirez ate 22% of the oranges, and Mr. Ramirez ate the rest. What percent of the oranges did Mr. Ramirez eat? 70.6% 25 20%

  27. Lesson Quiz: Part II 4.Rada is 170% as tall as her brother Raj. Raj is 0.82 m tall. To the nearest tenth of a meter, how tall is Rada? 5.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? 1.4 m 4%

More Related