7th Grade Percents 2015-11-30 www.njctl.org Slide 3 / 157 Table - PDF document

Slide 1 / 157 Slide 2 / 157 7th Grade Percents 2015-11-30 www.njctl.org Slide 3 / 157 Table of Contents Click on the topic to go to that section Relating Fractions, Decimals and Percents Three Types of Percent Problems Percent of Change Representing Percent Equations Algebraically Applied Percent of Decrease Applied Percent of Increase Real-life Application Problems Glossary

Slide 4 / 157 Relating Fractions, Decimals & Percents Return to table of contents Slide 5 / 157 Helping you remember... Fill in each box below with an example of the process described. % to a fraction % to a decimal fraction to a % decimal to a % Slide 6 / 157 Ordering Order the numbers from least to greatest. 0.15 12.5% 0.095 In order to do this, they must all be in the same form. Let's turn them all into percents: 15% 12.5% 16% 9.5% So least to greatest: 9.5% 12.5% 15% 16% 0.095 12.5% 0.15

Slide 7 / 157 1 Find the lowest value. A 5% B 1/2 C .5% D .05 Slide 8 / 157 2 Find the greatest value. A 120% B 1.02 C .2% D 1.19 Slide 9 / 157 3 Find the greatest value. A 6% B .6 C 60 D 6

Slide 10 / 157 4 Find the lowest value. A 2% B .2 C .02 D .2% Slide 11 / 157 5 Find the lowest value. A 50% B 500% C 50.0 D 50.01 Slide 12 / 157

Slide 13 / 157 Examples Express each fraction as a percent: 1) 2) 3) click click click Slide 14 / 157 6 Express as a fraction. Slide 15 / 157 7 Express as a decimal.

Slide 16 / 157 8 Express as a percent. Slide 17 / 157 9 Express as a decimal. Slide 18 / 157 10 Express as a percent.

Slide 19 / 157 11 Express as a percent. Slide 20 / 157 Three Types of Percent Problems Return to table of contents Slide 21 / 157 Types of Percent Problems 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 whole 4 is 60% of what number? 3. Find the percent 18 is what percent of 28?

Slide 22 / 157 Types of Percent Problems Two words that will occur in these types of problems are: " is " " 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. Slide 23 / 157 Finding the Part... Slide 24 / 157 Find the Part Examples: Find 40% of 60 Write a mathematical sentence .40 60 = 24 Click 20% of 90 Write a mathematical sentence .20 90 = 18 Click

Slide 25 / 157 Write a Mathematical Sentence What is 10% of 88? X = .10 88 X = 8.8 Try these: Find 12% of 70 What is 40% of 28? Slide 26 / 157 Slide 27 / 157

Slide 28 / 157 Proportion Method Steps % is = 1. Set up the proportion as shown. 100 of Note: You can use this box to solve many problems involving percents! 2. Substitute given values into the proportion. Note: Try to find the numbers that are attached to the words/symbols: is, of, or percent. 3. Solve the proportion. Slide 29 / 157 Proportion Method Example Example: What is 25% of 400? Steps = % is ? 25 1. Set up the proportion. 100 of 400 100 2. Substitute. Click on each box to see if you substituted correctly. What is 25% of 400? 3. Solve. click 400 x 25 = 100w 10,000 = 100w 10,000/100 = w 100 = w Slide 30 / 157 Proportion Method Example Example: What is 32% of 300? Steps is = % 1. Set up the proportion. ? 32 of 100 300 100 2. Substitute. Click on each box to see if you substituted correctly. What is 32% of 300? 3. Solve. 300 x 32 = 100w click 9,600 = 100w 9600/100 = w 96 = w

Slide 31 / 157 Proportion Method - Try It Try it: What is 20% of 180? Steps = % is 1. Set up the proportion. 100 of 2. Substitute. 3. Solve. Slide 32 / 157 12 Find 30% of 45. Slide 33 / 157 13 What is 15% of 90?

Slide 34 / 157 14 Find the greater value. A 20% of 16 B 10% of 90 C 25% of 40 D 100% of 7 Slide 35 / 157 15 Find the greater value. A 2% of 1000 B 5% of 500 C 10% of 300 D 15% of 100 Slide 36 / 157 16 Identify any values that are equal. A What is 40% of 80? B 60% of 70 C 25% of 128 D 200% of 16

Slide 37 / 157 Finding the Whole... Slide 38 / 157 Finding the Whole 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 Slide 39 / 157 Finding the Whole Try This: 100 is 20% of what number? 100 = .20 x 100 = x .20 x = 500

Slide 40 / 157 17 56 is 70% of what? Slide 41 / 157 18 12% of what number is 6? Slide 42 / 157 19 65% of what number is 10?

Slide 43 / 157 20 27 is 150% of what number? Slide 44 / 157 21 1% of what number is 12? Slide 45 / 157 Finding the Percent...

Slide 46 / 157 Finding the Percent 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% Slide 47 / 157 Finding the Percent 60 is what percent of 15? 60 = x 15 60 = X 15 4 = X 400% = X Slide 48 / 157 22 What percent of 3 is 12?

Slide 49 / 157 23 30 is what percent of 36? Slide 50 / 157 24 What percent of 18 is 180? Slide 51 / 157 25 2 is what percent of 1?

Slide 52 / 157 26 What percent of 25 is 20? Slide 53 / 157 Percent Problems 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? Slide 54 / 157 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?

Slide 55 / 157 28 Find the greatest percentage value. 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? Slide 56 / 157 29 Find 20% of 78. Slide 57 / 157 30 Eight is what percent of 28?

Slide 58 / 157 31 What number is 3% of 17? Slide 59 / 157 32 Find 27% of 54. Slide 60 / 157 33 23 is what percent of 200?

Slide 61 / 157 34 What percent is 35 of 20? Slide 62 / 157 35 Fifty six percent of what number is 40? Slide 63 / 157 36 Forty five is 30% of what number?

Slide 64 / 157 37 Sixty two percent of 40 is what number? A 24.8 B .0155 C 24.8% D 15.5 Slide 65 / 157 Percent of Change Return to table of contents Slide 66 / 157 Percent of Change Percent of Change is the ratio of the amount of increase or decrease to the original amount. It is an increase when the new amount is larger than the original and a decrease when the new amount is smaller than the original. To find the percent of change, use the following proportion: Percent of change: Amount of increase or decrease = % Original Amount 100

Slide 67 / 157 Percent of Change Find the percent of change (be sure to label your answer as an increase or decrease). Examples: Original amount: 20 Original amount: 40 New amount: 30 New amount: 10 Percent of change= Percent of change= Slide 68 / 157 Percent of Change Identify the percent of change as an increase or decrease. Then find the percent of change. 1. Original: 45 New: 75 2. Original: 100 New: 42 3. Original: 58 New: 75 Slide 69 / 157 Percent of Change Try This! A CD's original price was $12.99. It is now on sale for $10.99. What is the percent of change?

Slide 70 / 157 Percent of Change Try This! A student's first test grade was 60. The second test grade was an 85. What was the percent of change? Slide 71 / 157 38 In 2005, the price of a McDonald's hamburger was $0.89. In 2010, the price of a McDonald's hamburger was $1.19. What was the percent of change? Slide 72 / 157 39 Original Amount: 500 New: 700 Find the percent of change.

Slide 73 / 157 40 Original Amount: 52 New: 17 Find the percent of change. Slide 74 / 157 41 The number of students who attended FHS in 2010 was 1405. In 2011, 1380 students attended FHS. What was the percent of change in student enrollment? Slide 75 / 157 42 Find the percent of change. Original price: $120 Sale price: $75

Slide 76 / 157 43 Find the percent of change. Original price: $80 Sale price: $50 Slide 77 / 157 44 A stereo, originally priced at $360, is on sale for $200. What is the percent of change? Slide 78 / 157 Representing Percent Equations Algebraically Return to table of contents