Skip to the main content
PeabodyMake a free story

🍕 7th grade math · Fractions & Decimals

Sales, tips and percent change

Percent change = change ÷ original. From 40 to 50: change 10, 10 ÷ 40 = 0.25, so a 25% increase. A 15% increase on 40: 15% of 40 = 6, so 40 + 6 = 46. For a decrease, subtract.

Worked example

The population of a town changes from 100 to 110. By what percent did it increase?
Answer: 10%
Percent change = change ÷ original. From 100 to 110 is a change of 10. 10 ÷ 100 = 0.1 = 10%, an increase.

For grown-ups: Multistep percent problems: tax, tips, markups, discounts, percent increase/decrease, simple interest. Below: three problems to try with the worked answers, and a free printable sheet. Children can practise the same skill as a game, with no sign-up and no ads.

  • CCSS 7.RP.A.3
What this practises, for teachers

Practices multistep percent problems: tax, tips, markups, discounts, percent increase/decrease, simple interest (7.RP.A.3). A printable sheet with its answer key, worked answers on the page, no accounts.

▶ Practise it

For your class

🖨️ Printable sheet and key

More printables, with answer keys, for this grade:

Try three

  1. A jacket costs $50. The price drops by 10%. What is the new price?
    Show the answer and how
    Answer: $45.00
    10% of $50 is 0.1 × $50 = $5. Take it away: $50 − $5 = $45. (Same as 0.9 × $50.)
  2. A plant is 60 cm. It grows by 20%. How many cm tall is it now?
    Show the answer and how
    Answer: 72 cm
    20% of 60 cm is 0.2 × 60 cm = 12 cm. Add it on: 60 cm + 12 cm = 72 cm. (Same as 1.2 × 60 cm.)
  3. A town has 3000 people. Its population grows by 5%. How many people live there now?
    Show the answer and how
    Answer: 3150
    5% of 3000 is 0.05 × 3000 = 150. Add it on: 3000 + 150 = 3150. (Same as 1.05 × 3000.)

Before and after

Learn first: Percent of a number (6th)

Name: ____________________Date: ____________Score: ____ / 12

Sales, tips and percent change (7th grade)

  1. A plant is 50 cm. It is trimmed back by 50%. How many cm tall is it now?
  2. The height of a plant changes from 40 cm to 36 cm. By what percent did it decrease?
  3. A plant is 80 cm. It grows by 25%. How many cm tall is it now?
  4. The height of a plant changes from 120 cm to 90 cm. By what percent did it decrease?
  5. A town has 200 people. Its population shrinks by 50%. How many people live there now?
  6. A town has 400 people. Its population shrinks by 25%. How many people live there now?
  7. The price of a jacket changes from $20 to $22. By what percent did it increase?
  8. The height of a plant changes from 60 cm to 66 cm. By what percent did it increase?
  9. A town has 7500 people. Its population shrinks by 30%. How many people live there now?
  10. The height of a plant changes from 45 cm to 51.75 cm. By what percent did it increase?
  11. A plant is 90 cm. It is trimmed back by 20%. How many cm tall is it now?
  12. The height of a plant changes from 150 cm to 60 cm. By what percent did it decrease?

Answer key

  1. 25 cm
  2. 10%
  3. 100 cm
  4. 25%
  5. 100
  6. 300
  7. 10%
  8. 10%
  9. 5250
  10. 15%
  11. 72 cm
  12. 60%

More 7th grade skills: all 7th grade math skills, or every grade at math skills.