7th Percents Unit Review

​Understanding Percents

By Erin Moots

Understanding Percents

​Find the percent/Find the percent of a number

• When a question asks you to FIND THE PERCENT, think about how you find a percent here at school when you get a paper back.

• Remember the importance of the word "OF". It means multiply!

• Also, remember you can DIVIDE if given the percent and the answer.
  

Multiple Choice

What is 10% of 40?

• 40

• 0.4

• 4

• 1.4

Multiple Choice

What is 20% of 50

• 10

• 25

• 5

• 15

Multiple Choice

What is 12% of 60

• 72

• 7.2

• 6

• 6.2

Multiple Choice

A student got 70% of the problems on a math test correct.  She got 21 problems correct.  How many questions were on the test?

• 30
• 20
• 25
• 10

Fill in the Blanks

What is 45% of 85

Fill in the Blanks

What is 72% of 54?

Fill in the Blanks

A kindergarten class has 9 girls and 11 boys. What percent of the class are girls?

Fill in the Blanks

Coach Thomas has a player who made 9 free throw shots out of 15 in tryouts. What percent of the shots did the player make?

Multiple Choice

15 out of 25 boys chose to go swimming at camp. What percent is that?

• 15%
• 20%
• 45%
• 60%

Multiple Choice

Henry has 15 lawns mowed out of a total of 60 lawns. What percent is that?

• 15
• 25
• 19
• 4

This is the same as "is over of" but we use this one for word problems.

​"Part over whole"

You can always use cross multiply with the percent proportion to find a missing number. This is for non-word problems.

​"Is over of"

The Percent Proportion

Multiple Choice

Which proportion matches the following:

What is 90% of 250?

• $$\frac{90}{250}=\frac{x}{100}$$

• $$\frac{250}{x}=\frac{90}{100}$$

• $$\frac{x}{250}=\frac{90}{100}$$

Multiple Choice

Nancy earned 60 points on her last test. If there were 75 possible points, what was her percent grade?

• 20%
• 40%
• 60%
• 80%

Multiple Choice

In the United States, 13 out of every 20 cans are recycled. What percent of cans are recycled?

• 55%

• 63%

• 65%

• 85%

Multiple Choice

 Shirley spelled 12 of her 15 spelling words correctly on the test.  What percent grade did Shirley get on the test?

• 40%
• 50%
• 80%
• 60%

Multiple Choice

In the question,
"35 is what percent of 40?"
What is the 40?

• Part
• Whole
• Percent
• Nothing 

Multiple Choice

How do you set up percent proportions?

• (part/whole) = (%/100)
• (%/part) = (100/whole)
• (part/part) = (whole/whole)
• (whole/part) = (%/100)

• How much ERROR was made in a situation

• Subtract the numbers

• Divide by the ACTUAL

• Multiply by 100

​Percent Error

• We're calculating the PERCENT of change, not just the amount.

• Subtract the numbers

• Divide by the ORIGINAL

• Multiply by 100

​Percent of Change

Percent of Change/Error

Multiple Choice

Question 1 - Chesnie was 50 inches to start the school year and is now 55 inches. What is her percent of change to nearest whole number?

• 5 % INCREASE

• 10 % INCREASE

• 9 % INCREASE

• 91 % INCREASE

Multiple Choice

Question 2 - Wes scored 30 points in his video game yesterday and today he scored 24 points. What is his percent change?

• 6 % INCREASE

• 25 % INCREASE

• 20 % INCREASE

• 80 % INCREASE

Multiple Choice

Question 3 - Jake estimated a tree to be 80 inches tall and it is actually 92 inches tall. What is his percent of error?

• 13 %

• 15 %

• 20 %

• 10 %

Multiple Choice

Question 4 - Ariadna guessed that there were 43 gummy worms in a bag and there were 38 in the bag. What is her percent of error to nearest whole percent?

• 5 %

• 12 %

• 13 %

• 88 %

Multiple Choice

Question 5 - Owen had $75 and now has $120. What is his percent change to nearest whole number percent?

• 63 %

• 55 %

• 60 %

• 38 %

Multiple Choice

Question 6 - Reese decided to clean her room and to donate some items. She had 16 pairs of shoes to start and now has 12 pairs of shoes. By what percent did she decrease her shoes?

• 4 %

• 75 %

• 33 %

• 25 %

This gets you directly to the answer!

#(1 + %) or #(1-%)

​1-step method

This gets you the increase or decrease - multiply first

Then add or subtract to get the total

​2-step method

Percent Increase/Decrease

Multiple Choice

The original price of a pair of shoes is $29.99 and their is a mark down of 10% because the shop is having a black friday sale. What is the amount of money being taken off the original price?

• $0.29
• $2.99
• $1.99

Multiple Choice

A notebook is on sale for $1.50 with a 20% mark up. What is the amount of the mark up? 

• $0.30
• $1.30
• $3

Multiple Choice

How much tip should you leave if you want to tip 23% at Applebee's on a $27.31 bill?

• $6.28
• $33.59
• $21.03

Multiple Choice

Jessica is wanting to buy a $10.00 box of candy. The sales tax is 5%. How much is the total for the candy?

• $15.00
• 11.00
• $12.00
• $10.50

Multiple Choice

Mr. Barrett bought a new battery for his car. The battery cost $72. Since batteries are a taxable item, he had to pay a sales tax of 7.5%. What was the total cost of the battery in dollars and cents?

• $79.50

• $5.40

• $77.40

• $66.60

Multiple Choice

Ralph buys a computer for $675. The sales tax rate is 6%. How much total did Ralph pay for the computer?

• 40.50
• 715.50
• 6.00
• 634.50

Multiple Choice

A PS4 costs $399. There is a 20% discount. What is the total cost?

• $379

• $79.80

• $319.20

• $478.80

Multiple Choice

Find the total cost of the meal. $ 75.45 steak dinner; 18% gratuity (tip). Round to the nearest cent.

• $ 13.58

• $ 89.03

• $ 61.87

• $135.80

Simple Interest

​Finding the amount of interest is a percent

• I = PRT

• I = interest.

• P = principle or the original amount of money

• R = rate or percent

• T = time

Fill in the Blanks

Caiden earned $475 from mowing lawns last summer. He deposited this money in an account that pays a simple interest rate of 3.8%. What will be the amount of interest earned after 15 years?

Fill in the Blanks

Emily’s parents put $1500 in her bank account for college tuition at a simple interest rate of 8.25%. What will be the balance after 18 years?

Fill in the Blanks

Mark took out a loan for $25,690 to purchase a new truck at a simple interest rate of 5.2%. How much interest will he pay on his truck after 5 years?

Fill in the Blanks

The Henley’s took out a new home loan for $195,000 at a simple interest rate of 4.3%. How much will they pay in interest after 30 years?

Fill in the Blanks

Kennedy won $3,000 from a radio contest. If she puts this money in a bank account that earns 2.9% simple interest, how much will she have in total in her account at the end of 10 years?