Percent increase, percent decrease and percent error

Answer Key - Grade 7 Math Worksheet - Building Confidence

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

1. 1.

   Row 100 | 60; row 10 | 6; then a blank row for the new amount. Ari's cookie recipe uses 60 grams of flour. Ari makes a bigger batch with 30% more flour. How many grams of flour does the bigger batch use?

   78
2. 2.

   Row 100 | 40; row 5 | 2; then a blank row for the new amount. Bo's class pond has 40 water lilies. After a sunny month it has 25% more water lilies. How many water lilies does the pond have now?

   50
3. 3.

   Row 100 | 80; row 10 | 8; then a blank row for the new amount. Jun's water bottle holds 80 ounces. Jun drinks 20% of the water before the bus. How many ounces are left?

   64
4. 4.

   Row 100 | 160; row 5 | 8; then a blank row for the new amount. Luz's library cart held 160 books. 15% were put back on the shelves. How many books are still on the cart?

   136
5. 5.

   Noah's bamboo shoot is 70 centimeters tall. A week later it is 50% taller. How tall is the shoot now?

   105
6. 6.

   Ren's class had 150 pencils. 20% of the pencils got lost in the great desk cleanup. How many pencils are left?

   120
7. 7.

   Zee's sunflower is 90 centimeters tall. A storm bends it so it is 10% shorter. How tall is the sunflower now?

   81
8. 8.

   Ari's town grew by 5% this year. By what number do you multiply last year's population to get this year's population?

   1.05
9. 9.

   Bo's recipe is made 20% bigger for a party. By what number do you multiply each amount to get the bigger recipe?

   1.2
10. 10.

    Jun's watering can leaks, so it holds 25% less water than before. By what number do you multiply the old amount of water to get the new amount?

    0.75