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Warm Up. Problem of the Day. Lesson Presentation. Lesson Quizzes. 19. __. 50. 3. __. 50. 1. __. 5. Warm Up Write each decimal as a percent and fraction. 1. 0.38 2. 0.06 3. 0.2. 38%,. 6%,. 20%,. Problem of the Day
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Warm Up Problem of the Day Lesson Presentation Lesson Quizzes
19 __ 50 3 __ 50 1 __ 5 Warm Up Write each decimal as a percent and fraction. 1. 0.38 2. 0.06 3. 0.2 38%, 6%, 20%,
Problem of the Day Lucky Jim won $16,000,000 in a lottery. Every year for 10 years he spent 50% of what was left. How much did Lucky Jim have after 10 years? $15,625
Sunshine State Standards MA.6.A.5.1 Use equivalent forms of fractions, decimals, and percents to solve problems. AlsoMA.6.A.5.3
% 100 is of = To find the percent one number is of another, use this proportion: Because you are looking for 45%of 420, 45 replaces the percent sign and 420 replaces “of.” The first denominator, 100, always stays the same. The “is” part is what you have been asked to find.
35 ___ First estimate your answer. Think: 35% = , which is close to , and 560 is close to 600. So about of the students participate in after-school sports. 100 1 __ 3 1 __ 3 1 __ 3 Additional Example 1: Application There are 560 students in Ella’s school. If 35% of the students participate in after-school sports, how many students participate in after-school sports? • 600 = 200 This is the estimate. Helpful Hint Think: “35 out of 100 is how many out of 560?”
35 s ___ ___ 100 560 100s 19,600 ____ _____ 100 100 Additional Example 1 Continued Now solve: Let s represent the number of students who participate in after-school sports. = The cross products are equal. 100 •s = 35 • 560 100s= 19,600 s is multiplied by 100. Divide both sides of the equation by 100 to undo multiplication. = s = 196 Since 196 is close to your estimate of 200, 196 is a reasonable answer. 196 students participate in after-school sports.
70 x ___ ___ 100 480 Check It Out: Example 1 There are 480 students in Tisha’s school. If 70% of the students participate in the fundraising program, how many students participate is that ? = ; 100x = 33,600; x = 336 students
% is ___ __ 100 of 25 20 ___ __ 100 m Additional Example 2: Application Johan is 25% of the way through his exercises. If he has exercised for 20 minutes so far, how much longer does he have to work out? 25% of the exercises are completed, so 20 minutes is 25% of the total time needed. = Set up a proportion. The “of” part is what you have been asked to find. = The cross products are equal. 100 • 20= 25 •m
2,000 25m _____ ____ 25 25 Additional Example 2 Continued 2,000= 25m m is multiplied by 25. Divide both sides by 25 to undo multiplication. = 80 = m The time needed for the exercises is 80 min. So far, the exercises have taken 20 min. Because 80 – 20 = 60, Johan will be finished in 60 min.
35 49 ___ __ 100 p Check It Out: Example 2A Katie has read 35% of a book. If she has read 49 pages, how many more pages does Katie have left to read? = ; 35p = 4,900; p = 140 pages 140 - 49 = 91 pages
75 6 __ ___ 100 l Check It Out: Example 2B Justin is 75% through washing and folding his laundry. If he has finished 6 loads, how many loads does he still need to do? = ; 75 l = 600; l = 8 loads 8 - 6 = 2 loads
Instead of using proportions, you can also multiply to find a percent of a number.
0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% 0 5 10 15 20 25 30 35 40 45 50 Additional Example 3: Multiplying to Find a Percent of a Number Find 36% of 50. Write the percent as a decimal. 36% = 0.36 0.36 • 50 Multiply using the decimal. 18 So 18 is 36% of 50. Check Use a model to check the answer.
Check It Out: Example 3A Find the percent of each number. 20% of 140 0.2 • 140 = 28
Check It Out: Example 3B Find the percent of each number. 45% of 900 0.45 • 900 = 405
Check It Out: Example 3C Find the percent of each number. 80% of 30 0.8 • 30 = 24
Check It Out: Example 3D Find the percent of each number. 15% of 150 0.15 • 150 = 22.5
Check It Out: Example 3E Find the percent of each number. 75% of 360 0.75 • 360 = 270
Check It Out: Example 3F Find the percent of each number. 30% of 170 0.3 • 170 = 51
Lesson Quizzes Standard Lesson Quiz Lesson Quiz for Student Response Systems
Lesson Quiz 1. Find 28% of 310. 2. Find 70% of 542. 3. Martha is taking a 100-question test. She has completed 60% of the test in 45 minutes. How much longer will it take her to finish the test? 4. Crystal has a collection of 72 pennies. If 25% of them are Canadian, how many Canadian pennies does she have? 86.8 379.4 30 min 18
Lesson Quiz for Student Response Systems 1. Identify 35% of 260. A. 35 B. 91 C. 260D. 295
Lesson Quiz for Student Response Systems 2. Identify 60% of 422. A. 253.2 B. 482 C. 362D. 25320
Lesson Quiz for Student Response Systems 3. Ella has to draw a flowchart as a part of an assignment. She has drawn 40% of the flowchart in 10 minutes. How much longer will it take her to complete the flowchart? A. 10 min B. 25 min C. 15 minD. 35 min
Lesson Quiz for Student Response Systems 4. Of 80 sheep in a field, 65% are ewes. How many ewes are there in the field? A. 28 ewes B. 52 ewes C. 65 ewesD. 108 ewes