270 likes | 382 Views
Tuesday, December 6th . Please come get new warm ups! Did you write down your homework?. Warm Up. Write each percent or decimal as a percent 1. 6/25 2. .3456. Corny Joke of the Day. What do you call a cow who can’t give milk? An “udder” failure!. Do you Remember?.
E N D
Tuesday, December 6th Please come get new warm ups! Did you write down your homework? Warm Up Write each percent or decimal as a percent 1. 6/25 2. .3456
Corny Joke of the Day What do you call a cow who can’t give milk? An “udder” failure!
Do you Remember? • When you make a decimal a percent you can really move the decimal _______ places to the ___________. • When you make a fraction a percent you want to make an equivalent fraction that has a denominator of _____________________.
Finding Percents Of a Number
The Meat of it • A percent proportion compares part of a quantity to the whole quantity, this is called the base. • The percent is always written as a fraction with a denominator of 100. “Per” means out of, and “cent” refers to 100. • Ratio Part (is) and whole (of)
Three ways you will see a problem Fill in your table!!!
Caution You will have to solve proportions to work with percents!
Proportion Review Cross Multiply and Divide
Part 1 Finding the percent
What percent of 6 is 3? 100 ÷ 2=50
You Try #1 What percent of 5 is 2?
You Try #2 What percent of 12 is 7?
Part 2 Finding the Part
What number is 50% of 6 6 ÷ 2=3
You Try #1 What number is 25% of 24
You Try #2 What number is 10% of 32
Part 3 Finding the Whole
You Try #1 What number is 11 25% of?
You Try #2 What number is 15 30% of
There are 480 students in Sara’s school. If 70% of the students participate in the fundraising program, how many students participate in the fundraising program?
s 70 33,600 100s ___ ___ _____ ____ 100 100 100 480 Answer Now solve: Let s represent the number of students who participate in the fundraising program. = The cross products are equal. 100 •s = 70 • 480 100s= 33,600 s is multiplied by 100. Divide both sides of the equation by 100 to undo multiplication. = s = 336 Since 336 is close to your estimate of 375, 336 is a reasonable answer. 336 students participate in the fundraising program.
Tanner 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?
is % 25 20 __ ___ ___ __ m 100 100 of Answer 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