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Class 8 Maths Worksheet: Cubes and Cube Roots

Maths worksheets lesson 59: Cubes and cube roots · Set 214 · 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 15 cm is cut into small cubes of edge 3 cm. How many small cubes are there?
  2. 2.What is the smallest whole number by which 25 must be multiplied to get a perfect cube?
  3. 3.A big cube of edge 6 cm is cut into small cubes of edge 3 cm. How many small cubes are there?
  4. 4.What is 10³? =
  5. 5.Which of these is a perfect cube? (a) 1728 (b) 1869 (c) 1902
  6. 6.What is the smallest whole number by which 320 must be multiplied to get a perfect cube?
  7. 7.Which of these is a perfect cube? (a) 4044 (b) 3720 (c) 3375
  8. 8.Which of these is a perfect cube? (a) 68 (b) 81 (c) 64
  9. 9.Which of these is a perfect cube? (a) 613 (b) 512 (c) 555
  10. 10.A big cube of edge 5 cm is cut into small cubes of edge 1 cm. How many small cubes are there?
  11. 11.A cube has a volume of 216 cubic cm. How long is each edge (in cm)?
  12. 12.A cube has a volume of 8000 cubic cm. How long is each edge (in cm)?
  13. 13.What is 12³? =
  14. 14.What is the smallest whole number by which 81 must be divided to get a perfect cube?
  15. 15.A big cube of edge 6 cm is cut into small cubes of edge 2 cm. How many small cubes are there?
  16. 16.What is the smallest whole number by which 4 must be multiplied to get a perfect cube?
  17. 17.What is 15³? =
  18. 18.A big cube of edge 20 cm is cut into small cubes of edge 4 cm. How many small cubes are there?
  19. 19.A cube has a volume of 64 cubic cm. How long is each edge (in cm)?
  20. 20.A big cube of edge 3 cm is cut into small cubes of edge 1 cm. How many small cubes are there?
  21. 21.A cube has a volume of 3375 cubic cm. How long is each edge (in cm)?
  22. 22.What is ∛27? =
  23. 23.A big cube of edge 4 cm is cut into small cubes of edge 2 cm. How many small cubes are there?
  24. 24.What is the smallest whole number by which 1944 must be divided to get a perfect cube?
  25. 25.What is ∛343? =
  26. 26.Which of these is a perfect cube? (a) 286 (b) 231 (c) 216
  27. 27.Which of these is a perfect cube? (a) 880 (b) 862 (c) 729
  28. 28.What is ∛4913? =
  29. 29.What is 3³? =
  30. 30.What is ∛10648? =
  31. 31.Which of these is a perfect cube? (a) 1463 (b) 1337 (c) 1331
  32. 32.What is ∛4096? =
  33. 33.What is 9³? =
  34. 34.What is 19³? =
  35. 35.Which of these is a perfect cube? (a) 1113 (b) 1169 (c) 1000
  36. 36.A cube has a volume of 6859 cubic cm. How long is each edge (in cm)?
  37. 37.What is ∛13824? =
  38. 38.What is 16³? =
  39. 39.A cube has a volume of 125 cubic cm. How long is each edge (in cm)?
  40. 40.What is ∛9261? =

Answer key

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

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