← Cubes and cube roots lesson New set →

Class 8 Maths Worksheet: Cubes and Cube Roots

Maths worksheets lesson 59: Cubes and cube roots · Set 109 · 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 5³? =
  2. 2.What is ∛125? =
  3. 3.What is 16³? =
  4. 4.What is the smallest whole number by which 576 must be multiplied to get a perfect cube?
  5. 5.What is the smallest whole number by which 3125 must be divided to get a perfect cube?
  6. 6.What is ∛64? =
  7. 7.What is 10³? =
  8. 8.What is the smallest whole number by which 864 must be divided to get a perfect cube?
  9. 9.What is the smallest whole number by which 10584 must be divided to get a perfect cube?
  10. 10.What is the smallest whole number by which 32 must be divided to get a perfect cube?
  11. 11.What is 15³? =
  12. 12.A big cube of edge 2 cm is cut into small cubes of edge 1 cm. How many small cubes are there?
  13. 13.A big cube of edge 12 cm is cut into small cubes of edge 2 cm. How many small cubes are there?
  14. 14.A big cube of edge 4 cm is cut into small cubes of edge 1 cm. How many small cubes are there?
  15. 15.What is 3³? =
  16. 16.What is ∛8? =
  17. 17.What is the smallest whole number by which 375 must be multiplied to get a perfect cube?
  18. 18.Which of these is a perfect cube? (a) 274 (b) 323 (c) 216
  19. 19.Which of these is a perfect cube? (a) 1728 (b) 1897 (c) 1768
  20. 20.What is 9³? =
  21. 21.A cube has a volume of 5832 cubic cm. How long is each edge (in cm)?
  22. 22.What is ∛15625? =
  23. 23.What is the smallest whole number by which 1512 must be divided to get a perfect cube?
  24. 24.What is 14³? =
  25. 25.What is 20³? =
  26. 26.Which of these is a perfect cube? (a) 512 (b) 612 (c) 643
  27. 27.Which of these is a perfect cube? (a) 27 (b) 29 (c) 33
  28. 28.A big cube of edge 3 cm is cut into small cubes of edge 1 cm. How many small cubes are there?
  29. 29.What is ∛8000? =
  30. 30.What is ∛4096? =
  31. 31.What is ∛12167? =
  32. 32.What is ∛216? =
  33. 33.Which of these is a perfect cube? (a) 1331 (b) 1529 (c) 1678
  34. 34.Which of these is a perfect cube? (a) 729 (b) 901 (c) 852
  35. 35.A big cube of edge 18 cm is cut into small cubes of edge 3 cm. How many small cubes are there?
  36. 36.Which of these is a perfect cube? (a) 469 (b) 343 (c) 352
  37. 37.What is the smallest whole number by which 16 must be multiplied to get a perfect cube?
  38. 38.What is ∛2197? =
  39. 39.What is ∛2744? =
  40. 40.What is 19³? =

Answer key

  1. 125
  2. 5
  3. 4096
  4. 3
  5. 25
  6. 4
  7. 1000
  8. 4
  9. 49
  10. 4
  11. 3375
  12. 8
  13. 216
  14. 64
  15. 27
  16. 2
  17. 9
  18. 216
  19. 1728
  20. 729
  21. 18
  22. 25
  23. 7
  24. 2744
  25. 8000
  26. 512
  27. 27
  28. 27
  29. 20
  30. 16
  31. 23
  32. 6
  33. 1331
  34. 729
  35. 216
  36. 343
  37. 4
  38. 13
  39. 14
  40. 6859

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