Square roots, cube roots and equations like x² = 49

Answer Key - Grade 8 Math Worksheet - Building Confidence

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

1. 1.

   Bo builds a solid cube from 64 toy blocks. The strip ? × ? × ? = 64 is shown. How many blocks long is each edge (the cube root of 64)?

   4
2. 2.

   In math club, Jun solves x² = 64. The strip x × x = 64 is shown. What are both values of x? Type them as a list.

   8, -8
3. 3.

   In math club, Kira solves x² = 100. The strip x × x = 100 is shown. What are both values of x? Type them as a list.

   10, -10
4. 4.

   In math club, Luz solves x² = 144. The strip x × x = 144 is shown. What are both values of x? Type them as a list.

   12, -12
5. 5.

   Milo's worksheet asks for √(81/100), the number that times itself makes 81/100. What is √(81/100)?

   9/10
6. 6.

   Noah's worksheet asks for √(9/49), the number that times itself makes 9/49. What is √(9/49)?

   3/7
7. 7.

   Pia's worksheet asks for √(1/25), the number that times itself makes 1/25. What is √(1/25)?

   1/5
8. 8.

   Ren's worksheet asks for ∛8, the number that three times makes 8. What is ∛8?

   2
9. 9.

   Tala's worksheet asks for ∛-64, the number that three times makes -64. What is ∛-64?

   -4
10. 10.

    Zee's worksheet asks for ∛-8, the number that three times makes -8. What is ∛-8?

    -2