← Cubes and cube roots lesson New set →

Class 8 Maths Worksheet: Cubes and Cube Roots

Maths worksheets lesson 59: Cubes and cube roots · Set 675 · 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 15³? =
  2. 2.What is the smallest whole number by which 6125 must be divided to get a perfect cube?
  3. 3.Which of these is a perfect cube? (a) 2854 (b) 2744 (c) 2799
  4. 4.What is the smallest whole number by which 135 must be divided to get a perfect cube?
  5. 5.A big cube of edge 16 cm is cut into small cubes of edge 4 cm. How many small cubes are there?
  6. 6.A cube has a volume of 4096 cubic cm. How long is each edge (in cm)?
  7. 7.A big cube of edge 2 cm is cut into small cubes of edge 1 cm. How many small cubes are there?
  8. 8.What is 14³? =
  9. 9.What is 16³? =
  10. 10.What is the smallest whole number by which 3125 must be multiplied to get a perfect cube?
  11. 11.What is ∛729? =
  12. 12.A cube has a volume of 4913 cubic cm. How long is each edge (in cm)?
  13. 13.A cube has a volume of 64 cubic cm. How long is each edge (in cm)?
  14. 14.A big cube of edge 24 cm is cut into small cubes of edge 4 cm. How many small cubes are there?
  15. 15.Which of these is a perfect cube? (a) 1671 (b) 1360 (c) 1331
  16. 16.What is the smallest whole number by which 189 must be multiplied to get a perfect cube?
  17. 17.What is ∛10648? =
  18. 18.What is 5³? =
  19. 19.What is the smallest whole number by which 500 must be divided to get a perfect cube?
  20. 20.What is ∛3375? =
  21. 21.What is the smallest whole number by which 4 must be divided to get a perfect cube?
  22. 22.What is 2³? =
  23. 23.Which of these is a perfect cube? (a) 729 (b) 776 (c) 900
  24. 24.What is 12³? =
  25. 25.What is 7³? =
  26. 26.What is the smallest whole number by which 10584 must be multiplied to get a perfect cube?
  27. 27.Which of these is a perfect cube? (a) 2403 (b) 2197 (c) 2575
  28. 28.What is the smallest whole number by which 56 must be divided to get a perfect cube?
  29. 29.What is the smallest whole number by which 648 must be multiplied to get a perfect cube?
  30. 30.What is 4³? =
  31. 31.A cube has a volume of 2744 cubic cm. How long is each edge (in cm)?
  32. 32.A big cube of edge 18 cm is cut into small cubes of edge 3 cm. How many small cubes are there?
  33. 33.Which of these is a perfect cube? (a) 80 (b) 64 (c) 69
  34. 34.What is ∛2744? =
  35. 35.What is 6³? =
  36. 36.A big cube of edge 4 cm is cut into small cubes of edge 1 cm. How many small cubes are there?
  37. 37.What is 18³? =
  38. 38.What is 13³? =
  39. 39.A big cube of edge 4 cm is cut into small cubes of edge 2 cm. How many small cubes are there?
  40. 40.A big cube of edge 20 cm is cut into small cubes of edge 4 cm. How many small cubes are there?

Answer key

  1. 3375
  2. 49
  3. 2744
  4. 5
  5. 64
  6. 16
  7. 8
  8. 2744
  9. 4096
  10. 5
  11. 9
  12. 17
  13. 4
  14. 216
  15. 1331
  16. 49
  17. 22
  18. 125
  19. 4
  20. 15
  21. 4
  22. 8
  23. 729
  24. 1728
  25. 343
  26. 7
  27. 2197
  28. 7
  29. 9
  30. 64
  31. 14
  32. 216
  33. 64
  34. 14
  35. 216
  36. 64
  37. 5832
  38. 2197
  39. 8
  40. 125

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