← Cubes and cube roots lesson New set →

Class 8 Maths Worksheet: Cubes and Cube Roots

Maths worksheets lesson 59: Cubes and cube roots · Set 636 · 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.What is the smallest whole number by which 675 must be divided to get a perfect cube?
  2. 2.A big cube of edge 2 cm is cut into small cubes of edge 1 cm. How many small cubes are there?
  3. 3.Which of these is a perfect cube? (a) 2022 (b) 1749 (c) 1728
  4. 4.What is 9³? =
  5. 5.What is the smallest whole number by which 648 must be divided to get a perfect cube?
  6. 6.What is the smallest whole number by which 40 must be divided to get a perfect cube?
  7. 7.A cube has a volume of 3375 cubic cm. How long is each edge (in cm)?
  8. 8.What is ∛8? =
  9. 9.Which of these is a perfect cube? (a) 152 (b) 125 (c) 126
  10. 10.What is the smallest whole number by which 864 must be multiplied to get a perfect cube?
  11. 11.Which of these is a perfect cube? (a) 343 (b) 418 (c) 480
  12. 12.What is 4³? =
  13. 13.Which of these is a perfect cube? (a) 933 (b) 769 (c) 729
  14. 14.What is the smallest whole number by which 10584 must be divided to get a perfect cube?
  15. 15.What is ∛2197? =
  16. 16.What is ∛1000? =
  17. 17.What is 19³? =
  18. 18.Which of these is a perfect cube? (a) 1647 (b) 1558 (c) 1331
  19. 19.What is ∛12167? =
  20. 20.What is 2³? =
  21. 21.What is ∛512? =
  22. 22.A big cube of edge 24 cm is cut into small cubes of edge 4 cm. How many small cubes are there?
  23. 23.A cube has a volume of 5832 cubic cm. How long is each edge (in cm)?
  24. 24.A cube has a volume of 729 cubic cm. How long is each edge (in cm)?
  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 ∛216? =
  27. 27.What is ∛27? =
  28. 28.A cube has a volume of 8000 cubic cm. How long is each edge (in cm)?
  29. 29.What is 12³? =
  30. 30.Which of these is a perfect cube? (a) 2197 (b) 2562 (c) 2444
  31. 31.A cube has a volume of 1728 cubic cm. How long is each edge (in cm)?
  32. 32.What is the smallest whole number by which 448 must be multiplied to get a perfect cube?
  33. 33.What is ∛343? =
  34. 34.A cube has a volume of 8 cubic cm. How long is each edge (in cm)?
  35. 35.A big cube of edge 8 cm is cut into small cubes of edge 4 cm. How many small cubes are there?
  36. 36.A cube has a volume of 343 cubic cm. How long is each edge (in cm)?
  37. 37.What is the smallest whole number by which 108 must be divided to get a perfect cube?
  38. 38.What is ∛6859? =
  39. 39.What is ∛5832? =
  40. 40.What is the smallest whole number by which 448 must be divided to get a perfect cube?

Answer key

  1. 25
  2. 8
  3. 1728
  4. 729
  5. 3
  6. 5
  7. 15
  8. 2
  9. 125
  10. 2
  11. 343
  12. 64
  13. 729
  14. 49
  15. 13
  16. 10
  17. 6859
  18. 1331
  19. 23
  20. 8
  21. 8
  22. 216
  23. 18
  24. 9
  25. 27
  26. 6
  27. 3
  28. 20
  29. 1728
  30. 2197
  31. 12
  32. 49
  33. 7
  34. 2
  35. 8
  36. 7
  37. 4
  38. 19
  39. 18
  40. 7

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