← Cubes and cube roots lesson New set →

Class 8 Maths Worksheet: Cubes and Cube Roots

Maths worksheets lesson 59: Cubes and cube roots · Set 29 · 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.Which of these is a perfect cube? (a) 151 (b) 178 (c) 125
  2. 2.What is 20³? =
  3. 3.What is ∛6859? =
  4. 4.Which of these is a perfect cube? (a) 2651 (b) 2519 (c) 2197
  5. 5.A cube has a volume of 64 cubic cm. How long is each edge (in cm)?
  6. 6.What is ∛3375? =
  7. 7.A cube has a volume of 2744 cubic cm. How long is each edge (in cm)?
  8. 8.What is 18³? =
  9. 9.What is ∛343? =
  10. 10.What is 7³? =
  11. 11.What is the smallest whole number by which 7 must be divided to get a perfect cube?
  12. 12.A cube has a volume of 8000 cubic cm. How long is each edge (in cm)?
  13. 13.What is ∛2197? =
  14. 14.What is 16³? =
  15. 15.What is 2³? =
  16. 16.What is the smallest whole number by which 1944 must be multiplied to get a perfect cube?
  17. 17.What is ∛15625? =
  18. 18.Which of these is a perfect cube? (a) 343 (b) 379 (c) 443
  19. 19.A cube has a volume of 4096 cubic cm. How long is each edge (in cm)?
  20. 20.What is the smallest whole number by which 7 must be multiplied to get a perfect cube?
  21. 21.What is the smallest whole number by which 1323 must be divided to get a perfect cube?
  22. 22.Which of these is a perfect cube? (a) 2107 (b) 1808 (c) 1728
  23. 23.A big cube of edge 9 cm is cut into small cubes of edge 3 cm. How many small cubes are there?
  24. 24.Which of these is a perfect cube? (a) 618 (b) 579 (c) 512
  25. 25.A big cube of edge 3 cm is cut into small cubes of edge 1 cm. How many small cubes are there?
  26. 26.What is 5³? =
  27. 27.What is the smallest whole number by which 5 must be multiplied to get a perfect cube?
  28. 28.What is 4³? =
  29. 29.What is ∛4913? =
  30. 30.What is the smallest whole number by which 320 must be multiplied to get a perfect cube?
  31. 31.What is ∛8000? =
  32. 32.What is the smallest whole number by which 54 must be multiplied to get a perfect cube?
  33. 33.Which of these is a perfect cube? (a) 737 (b) 790 (c) 729
  34. 34.A big cube of edge 6 cm is cut into small cubes of edge 1 cm. How many small cubes are there?
  35. 35.What is ∛64? =
  36. 36.A cube has a volume of 27 cubic cm. How long is each edge (in cm)?
  37. 37.A big cube of edge 12 cm is cut into small cubes of edge 2 cm. How many small cubes are there?
  38. 38.What is 9³? =
  39. 39.A cube has a volume of 3375 cubic cm. How long is each edge (in cm)?
  40. 40.What is the smallest whole number by which 448 must be multiplied to get a perfect cube?

Answer key

  1. 125
  2. 8000
  3. 19
  4. 2197
  5. 4
  6. 15
  7. 14
  8. 5832
  9. 7
  10. 343
  11. 7
  12. 20
  13. 13
  14. 4096
  15. 8
  16. 3
  17. 25
  18. 343
  19. 16
  20. 49
  21. 49
  22. 1728
  23. 27
  24. 512
  25. 27
  26. 125
  27. 25
  28. 64
  29. 17
  30. 25
  31. 20
  32. 4
  33. 729
  34. 216
  35. 4
  36. 3
  37. 216
  38. 729
  39. 15
  40. 49

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