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Three Types of Percent Problems Day 2. Remember, percents are "parts of a whole". The part is the numerator and the whole is the denominator. 17% means 17 parts per 100 or We are going to solve problems involving percents . There are 3 types of problems:
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Remember, percents are "parts of a whole". The part is the numerator and the whole is the denominator. 17% means 17 parts per 100 or We are going to solve problems involving percents. There are 3 types of problems: 1. Find the part What number is 54% of 34? 2. Find the whole4 is 60% of what number? 3. Find the percent18 is what percent of 28?
Two words that will occur in these types of problems are "is" and "of". These words have specific meanings in math. "Is" means equals (=) "Of" means multiply To solve a percent problem, translate the words into an equation. Change the following: 1. Percent into a decimal 2. "is" to "=" 3. "of" to " " 4. Unknown to "x" Then, solve the equation.
Examples: Find 40% of 60 Write a mathematical sentence Click Click 60 = 24 .40 20% of 90 Write a mathematical sentence .20 90 = 18
What is 10% of 88? Write a mathematical sentence X = .10 88 X = 8.8 Try these: Find 12% of 70 What is 40% of 28?
Another Method: You can also solve percent problems by setting up a proportion. Since percents are parts of a whole, you can create the following proportion:
When figuring out which is the "part" and which is the "whole", remember that you take a percent of the whole and the answer is the part. In other words, the whole is with the word "of" and the part is with the word "is".
Proportion Method Steps 1. Set up the proportion as shown. 2. Substitute given values into the proportion. 3. Solve the proportion. = % is 100 of Note: You can use this box to solve many problems involving percents! Note: Try to find the numbers that are attached to the words/symbols: is, of, or percent.
Example: What is 25% of 400? Steps 1. Set up the proportion. 2. Substitute. 3. Solve. ? 25 % is = 400 100 100 of Click on each box to see if you substituted correctly. What is 25% of 400? 400 x 25 = 100w 10,000 = 100w 10,000/100 = w 100 = w Click
Example: What is 32% of 300? Steps 1. Set up the proportion. 2. Substitute. 3. Solve. ? 32 % is = 300 100 100 of Click on each box to see if you substituted correctly. What is 32% of 300? 300 x 32 = 100w 9,600 = 100w 9600/100 = w 96 = w Click
Try it: What is 20% of 180? Steps 1. Set up the proportion. 2. Substitute. 3. Solve. % is = 100 of
12 Find 30% of 45
13 What is 15% of 90?
14 Find the greater value. A 20% of 16 B 10% of 90 C 25% of 40 D 100% of 7
15 Find the greater value. A 2% of 1000 B 5% of 500 C 10% of 300 D 15% of 100
Identify any values that are equal. 16 A What is 40% of 80? B 60% of 70 C 25% of 128 D 200% of 16
Remember, you can solve this by: 1. Translating into an equation 2. Setting up a proportion 40% of what number is 50? .40 X = 50 X = 50 .40 X = 125
Try This: 100 is 20% of what number? 100 = .20 x 100 = x .20 x = 500
17 56 is 70% of what?
18 12% of what number is 6?
19 65% of what number is 10?
21 1% of what number is 12?
Remember, you can solve this by: 1. Translating into an equation 2. Setting up a proportion What percent of 80 is 24? x 80 = 24 X = 24 80 X = .30 X = 30%
60 is what percent of 15? 60 = X 15 60 = X 15 4 = X 400% = X
22 What percent of 3 is 12?
23 30 is what percent of 36?
24 What percent of 18 is 180?
25 2 is what percent of 1?
26 What percent of 25 is 20?
You have just studied three different types of percent problems. Try all 3 types: 24 is 40% of what number? 42 is what percent of 840? What is 30% of 45?
27 Find the largest value. A What is 50% of 50? B What number is 45% of 60? C 30 is 60% of what number? D 25% of what number is 150?
Find the greatest percentage value. 28 A What percent of 30 is 18? B 60 is what percent of 90? C What percent of 70 is 210? D 1,000 is what percent of 100?
29 Find 20% of 78.
30 8 is what percent of 28?
31 What number is 3% of 17?
32 Find 27% of 54.
33 23 is what percent of 200?
34 What percent is 35 of 20?
35 56% of what number is 40?
36 45 is 30% of what number?
37 62% of 40 is what number? A 24.8 B .0155 C 24.8% D 15.5