Name ______Date ______Period ______

Percents

Study Guide

Section 1 – Percents, Decimals and Fractions

  1. Write each number as a decimal, percent and fraction in simplest form.

Percent / Decimal / Fraction
34%
.15
5%
4.2

Order the numbers from least to greatest.

  1. , 220%, 2.15
  1. 0.88, , 90%
  1. 0.68, 66%,

Sections 2 and 3 – The Percent Proportion and the Percent Equation

  1. What percent of 60 is 18?
  1. 40 is what percent of 32?
  1. What number is 70% of 70?
  1. 6 is 75% of what number?

  1. 15% of the school parking spaces are handicap spaces. The school has 18 handicap spaces. How many parking spaces are there?
  1. Of the 25 students on a field trip, 16 students bring cameras. What percent of the students bring cameras?

Section 4 – Percent Change and Error

Find the new amount

  1. 55 employees increased by 20%
  2. $25 decreased by 60%

  1. 15 customers increased by 200%
  2. 4200 fans increased by 5%

  1. Yesterday 270 concert tickets were sold. Today 216 tickets were sold.Find the percent of change in the number of tickets sold from yesterday to today.

Identify the percent of change as an increase or a decrease. Then find thepercent of change. Round to the nearest tenth of a percent, if necessary.

  1. 5 cups to 8 cups
  2. 150 pounds to 135 pounds

  1. The weather man predicts that it is going to snow 3.5 inches on Friday. It actually snowed 4.2 inches. What is the percent error? Round to the nearest tenth if necessary.
  1. Last year on Black Friday, the Apple store sold 15,072 I-pods. This year on Black Friday, the Apple store sold 16, 834 I-pods. What is the percent change? Round to the nearest tenth if necessary.
  1. At a carnival, Lauren guesses that there are 125 gumballs in a jar. When the gumballs are counted, the actual number in the jar is 152. Find the percent of error in Lauren’s guess. Round to the nearest tenth of a percent, if necessary.
    Section 5 –Percent Application

Find the missing quantity

  1. Original price: $50 31

Discount: 15%

Sale price:

  1. Original price: $93.75

Discount: 20%

Sale price:

Find the selling price

  1. Cost to store: $50

Markup: 10%

  1. Cost to store: $80

Markup: 60%

  1. Cost to store: $140

Markup: 125%

  1. Lisa goes out to lunch with a friend and their bill comes to $25.76. They have to pay 7% sales tax in addition to leaving an 18% on the pre-tax bill. Find the total cost of the bill.
  1. Jackson is buying a new pair of winter boots. The boots cost $52.45. Luckily, Jackson has a 15% off coupon. In addition, Jackson has to pay 7% sales tax. Find the total cost of the boots.
  1. The GAP buys a sweater for $18.95 from the manufacturer. They then markup the sweater by 80% percent before selling it to the customer. If the customer has a 10% off coupon, what is the final retail cost of the sweater?

Section 6 – Simple Interest

An account earns simple interest. For each problem below, find the interest earned and the balance of the account.

  1. $300 at 4% for 3 years
  2. $2000 at 3.5% for 4 years

Find the annual simple interest rate.

  1. I = $17, P = $500, t = 2 years.
  2. I = $426, P = $1200, t = 5 years

Find the amount of time.

  1. I = $60, P = $400, r = 5%
  2. I = $237.90, P = $1525, r = 2.6%

  1. You put $100 in an account. The account earns $2 simple interest in 6 months. What is the annual interest rate?

Answer Key

Percent / Decimal / Fraction
34% / 34 /
15% / .15 /
37.5% / .375 /
5% / .05 /
420% / 4.2 / 4
  1. 15, 22%,
  2. , 0.88, 90%
  3. , .68
  4. 30%
  5. 125%
  6. 49
  7. 8
  8. 120 parking spaces
  9. 64% of students bring cameras
  10. 66 employees
  11. $10
  12. 45 customers
  13. 3,990 fans
  14. -20%
  15. Increase of 60%
  16. Decrease by 10%
  17. 16.7% error
  18. Increase by 11.7%
  19. 17.8% error
  20. $42.76
  21. $75.00
  22. $55
  23. $128
  24. $315
  25. $32.20
  26. $47.70
  27. $30.70
  28. $36; $336
  29. $280; $2,280
  30. 1.7%
  31. 7.1%
  32. 3 years
  33. 6 years
  34. 4%