Percent increase, percent decrease and percent error

Answer Key - Grade 7 Math Worksheet

Circle the best answer, or write your answer on the line.

1. 1.

   Luz's class collected 150 cans in March and 12% more cans in April. How many cans did the class collect in April?

   168
2. 2.

   A storm knocked off 36% of the 250 apples on Noah's tree. How many apples are left?

   160
3. 3.

   Pia's bunch of grapes weighed 320 grams. Pia ate 45% of it on the hike. How many grams of grapes are left?

   176
4. 4.

   Ren's soccer league had 480 players, and 15% moved away over the summer. How many players are in the league now?

   408
5. 5.

   Ari's book club read 15 books last year and 60 books this year, because the new library opened. By what percent did the number of books increase?

   300
6. 6.

   Luz's paper stack had 80 sheets, and 72 sheets are left after a project. By what percent did the stack decrease?

   10
7. 7.

   Milo guesses that a jar holds 50 beans, but it really holds 40 beans. What is the percent error of the guess?

   25
8. 8.

   Pia weighs a rock and reads 52 grams on a scale. The rock's real mass is 50 grams. What is the percent error of the reading?

   4
9. 9.

   Ren times a race with a stopwatch and reads 84 seconds. The real time is 80 seconds. What is the percent error of the reading?

   5
10. 10.

    x is the number of pages Ari had left to read. After a long evening, Ari has 15% fewer pages left. Which expression gives the pages left now?

    • 1.15x
    • 0.85x
    • 0.15x
    • x − 0.15