7.3.1 finding the part
- 1. Lesson 7.3 , For use with pages 354-358 Solve the proportion. ANSWER 14 ANSWER 42 1. x 35 = 16 40 2. 24 x = 32 56
- 2. Math homework for the week of Nov. 14-18 Monday: 7.3 Finding the part. Homework– worksheet 59B-60 all. Tuesday: 7.3 Finding the percent. Homework– worksheet 61B-62 all. Wednesday: 7.3 Finding the total/base. Homework– worksheet 61B-62 all. Thursday: Review. Homework– worksheet 65B-66 all. Friday: Quiz over ratios, proportions and the three types of percent problems. (Proportion quiz corrections due.)
- 3. Finding the PART (that represents the percent) Section 7.3
- 4. Essential Questions Where are different situations percents are used in real life? As a consumer, why is it important for you to know about percents?
- 5. There are three different types of percent problems. Today we will be looking only one of these types – finding the part (or sometimes called the percentage). part % (of) total 100 Notice: the percent always goes over 100.
- 6. Some should be easy enough to do mentally . Others you will need to use a proportion. Can you do these in your head? 25% of 16 is_____ 50% of 60 is_____ 75% of 12 is_____ 33 1/3% of 21 is____ 100% of 17 is_____ 40% of 20 is_____
- 7. Some should be easy enough to do mentally . Others you will need to use a proportion. Can you do these in your head? 25% of 16 is_____ 50% of 60 is_____ 75% of 12 is_____ 33 1/3% of 21 is____ 100% of 17 is_____ 40% of 20 is_____ 8 30 9 7 17 4
- 8. part (is) % total (of) 100 8% of 50 is what number? a = 4 a 50 = 8 100 100a 8( 50) = 100a 400 = 100 100
- 9. part (is) % total (of) 100 What number is 25% of 36? a = 9 a 36 = 25 100 100a 25( 36) = 100a 900 = 100 100
- 10. part (is) % total (of) 100 ______ is 40% of 25. a = 10 a 25 = 40 100 100a 40( 25) = 100a 1,000 = 100 100
- 11. EXAMPLE 2 Finding Part of a Base SOLUTION a = 3400 School Newspaper Your school newspaper’s budget this year is 160% of last year’s budget, which was $2125 . What is this year’s budget? a 2125 = 160 100 100a 2125( 160) = 100a 340,000 = 100 100
- 12. A waiter may receive 15% of the bill for a tip. If your bill is $28.45. what would be an appropriate amount to leave for a tip? x = $4.27 x 28.45 = 15 100 100x 15( 28.45) = 100x 426.75 = 100 100
- 13. 65% of the students at LCMS agreed they did not study prior to tests. If there are 700 students in the building, how many students do not study prior to a test? How many “do” study? a = 455 a 700 = 65 100 100a 65( 700) = 100a 45,500 = 100 100
- 14. 65% of the customers bought at least one item that was on sale in the store. How many bought an item “on sale”? = 65 100
- 15. Water makes up about 95% of the weight of a watermelon. How many pounds of a 12-pound watermelon is NOT water? a = 0.6 a = 11.4 12 – 11.4 = 0.6 a 12 = 5 100 100a 5( 12) = 100a 60 = 100 100 a 12 = 95 100 100a 12( 95) = 100a 1140 = 100 100
- 16. Homework Worksheet 59-60 Page 59: Do column B Page 60: All You MUST show a PROPORTION for EVERY problem.