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Year 9 Maths — Cubes and cube roots

Cube a number, recognise a perfect cube, and find a cube root by prime factorisation.

Name: ________________________

  1. 1.Which of these is a perfect cube?

    • a) 512
    • b) 500
    • c) 1200
    • d) 600

  2. 2.What is 12 cubed?

  3. 3.What happens when a negative number is cubed?

    • a) A negative number cannot be cubed
    • b) It becomes zero
    • c) It turns positive
    • d) It stays negative

  4. 4.What is 7 cubed?

  5. 5.Sort each number by whether it is a perfect cube.

    Groups: A perfect cube · Not a perfect cube

    • 125
    • 500
    • 343
    • 100
    • 300
    • 216
    • 64

  6. 6.What is the cube root of 3375?

  7. 7.392 is 2 × 2 × 2 × 7 × 7. What is the smallest number, apart from zero, it must be multiplied by to make a perfect cube?

  8. 8.What is the cube root of -125?

Answer key — Year 9 Maths — Cubes and cube roots

  1. 1. a) 512
  2. 2. 1728
  3. 3. d) It stays negative
  4. 4. 343
  5. 5. 64 → A perfect cube; 100 → Not a perfect cube; 125 → A perfect cube; 216 → A perfect cube; 300 → Not a perfect cube; 343 → A perfect cube; 500 → Not a perfect cube
  6. 6. 15
  7. 7. 7
  8. 8. -5