← Cubes and cube roots lesson New set →

Class 8 Maths Worksheet: Cubes and Cube Roots

Maths worksheets lesson 59: Cubes and cube roots · Set 56 · 40 sums
TalentJR

The method (Threes make cubes): Cube: n × n × n. Cube root: the number that, used three times, gives the cube. Units digits: 1→1, 2→8, 3→7, 4→4, 5→5, 6→6, 7→3, 8→2, 9→9, 0→0 — use them to guess cube roots. Make a perfect cube: break into primes; multiply by what completes each group of three (or divide by what is left over). A big cube of edge a cut into small cubes of edge b gives (a ÷ b)³ small cubes.

NameDateTime takenScore ___ / 40
  1. 1.A big cube of edge 8 cm is cut into small cubes of edge 4 cm. How many small cubes are there?
  2. 2.Which of these is a perfect cube? (a) 34 (b) 27 (c) 45
  3. 3.What is the smallest whole number by which 192 must be multiplied to get a perfect cube?
  4. 4.What is the smallest whole number by which 250 must be divided to get a perfect cube?
  5. 5.What is the smallest whole number by which 7 must be divided to get a perfect cube?
  6. 6.What is 17³? =
  7. 7.What is the smallest whole number by which 128 must be divided to get a perfect cube?
  8. 8.What is 3³? =
  9. 9.What is the smallest whole number by which 648 must be multiplied to get a perfect cube?
  10. 10.A cube has a volume of 729 cubic cm. How long is each edge (in cm)?
  11. 11.What is 13³? =
  12. 12.A big cube of edge 6 cm is cut into small cubes of edge 3 cm. How many small cubes are there?
  13. 13.What is ∛15625? =
  14. 14.A big cube of edge 16 cm is cut into small cubes of edge 4 cm. How many small cubes are there?
  15. 15.What is the smallest whole number by which 500 must be multiplied to get a perfect cube?
  16. 16.A cube has a volume of 27 cubic cm. How long is each edge (in cm)?
  17. 17.A cube has a volume of 4913 cubic cm. How long is each edge (in cm)?
  18. 18.Which of these is a perfect cube? (a) 125 (b) 136 (c) 127
  19. 19.What is ∛9261? =
  20. 20.What is the smallest whole number by which 108 must be multiplied to get a perfect cube?
  21. 21.A cube has a volume of 2197 cubic cm. How long is each edge (in cm)?
  22. 22.What is 5³? =
  23. 23.What is ∛8000? =
  24. 24.What is ∛8? =
  25. 25.What is 8³? =
  26. 26.A big cube of edge 12 cm is cut into small cubes of edge 3 cm. How many small cubes are there?
  27. 27.Which of these is a perfect cube? (a) 2806 (b) 2744 (c) 3013
  28. 28.A cube has a volume of 216 cubic cm. How long is each edge (in cm)?
  29. 29.A big cube of edge 15 cm is cut into small cubes of edge 3 cm. How many small cubes are there?
  30. 30.What is the smallest whole number by which 49 must be multiplied to get a perfect cube?
  31. 31.Which of these is a perfect cube? (a) 65 (b) 64 (c) 100
  32. 32.Which of these is a perfect cube? (a) 1212 (b) 1000 (c) 1021
  33. 33.A cube has a volume of 1728 cubic cm. How long is each edge (in cm)?
  34. 34.Which of these is a perfect cube? (a) 317 (b) 216 (c) 245
  35. 35.What is 9³? =
  36. 36.What is the smallest whole number by which 864 must be multiplied to get a perfect cube?
  37. 37.What is ∛5832? =
  38. 38.A big cube of edge 12 cm is cut into small cubes of edge 2 cm. How many small cubes are there?
  39. 39.What is the smallest whole number by which 864 must be divided to get a perfect cube?
  40. 40.What is 15³? =

Answer key

  1. 8
  2. 27
  3. 9
  4. 2
  5. 7
  6. 4913
  7. 2
  8. 27
  9. 9
  10. 9
  11. 2197
  12. 8
  13. 25
  14. 64
  15. 2
  16. 3
  17. 17
  18. 125
  19. 21
  20. 2
  21. 13
  22. 125
  23. 20
  24. 2
  25. 512
  26. 64
  27. 2744
  28. 6
  29. 125
  30. 7
  31. 64
  32. 1000
  33. 12
  34. 216
  35. 729
  36. 2
  37. 18
  38. 216
  39. 4
  40. 3375

Free maths worksheets lessons, practice and worksheets at talentjr.in/maths-worksheets