7.3.1 finding the part

Lesson 7.3, For use with pages 354-358

ANSWER 14 ANSWER 42

1. x35 = 16

402. 24

x = 3256

Solve the proportion.

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.)

Finding the PARTFinding the PART(that represents the percent)(that represents the percent)

Section 7.3Section 7.3

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?

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 100Notice: the percent always goes over 100.

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_____

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

part (is) % total (of) 100

8% of 50 is what number?

a 50 = 8

100

a = 4

100a 8( 50)=

100a 400=

100 100

part (is) % total (of) 100

What number is 25% of 36?

a 36 = 25

100

a = 9

100a 25( 36)=

100a 900=

100 100

part (is) % total (of) 100

______ is 40% of 25.

a 25 = 40

100

a = 10

100a 40( 25)=

100a 1,000=

100 100

EXAMPLE 2 Finding Part of a Base

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?SOLUTION

a2125 = 160

100

a = 3400

100a 2125( 160)=

100a 340,000=

100 100

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?

x28.45

= 15

100

100x 15( 28.45)=

100x 426.75=100 100

x = $4.27

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?

a700 = 65

100

a = 455

100a 65( 700)=

100a 45,500=

100 100

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

Water makes up about 95% of the weight of a watermelon. How many pounds of a 12-pound watermelon is NOT water?

a 12 = 5

100

a = 0.6

100a 5( 12)=

100a 60=

100 100

a12 = 95

100

a = 11.4

100a 12( 95)=

100a 1140=

100 100

12 – 11.4 = 0.6

Homework

Worksheet 59-60

– Page 59: Do column B

– Page 60: All

– You MUST show a PROPORTION for EVERY problem.