6-6 Percents And Proportions

Warm-up Tuesday, October 27, 2009 

Solve each proportion

a)

25 x = 100 28

b)

98 .9 43 = x 100

c)

52 13 = 100 x

d)

x 27 = 100 150

Percents and Proportions Section 6-6 We will be able to find parts of wholes and percents or finding whole amounts

Basic Idea For tonight’s homework, you will see problems like these: 1. 2. 3.

What percent of 15 is 5? What is 12% of 60? 28 is 14% of what number?

We’ll use key words to solve these problems.

Basic Idea One very easy phrase to remember to solve these problems correctly is this: “Percent over one hundred equals is over of” It looks like this:

% is = 100 of

Let’s Try (examples) Let’s give it a try. 1.

What percent of 15 is 5?

% is = 100 of

so

x 5 = 100 15

Example 2 2.

What is 12% of 60?

% is = 100 of

so

12 x = 100 60

Example 3 3.

28 is 14% of what number?

% is = 100 of

so

14 28 = 100 x

Note on Language The book uses different language in its tool. It would use the phrase “percent over 100 equals part over whole”. It’s the same thing with different words. In this phrase “is” becomes “part” and “of” becomes “whole”.

Summary From page 317 (321) in your book.

Homework 

Please complete 



page 318 (322) #1-23 odd

REMEMBER… 

Odd problems have answers in the back of the book, so you must show your work to receive full credit on your homework!!!

Ticket to Leave a)

Find 300% of 50

b)

Find 60% of 15

c)

35% of what number is 52.5

d)

A bicycle cost $250 last year. The same bike costs $200 this year. What percent of last year’s cost is this year’s cost?