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Class 8 Maths Worksheet: Cubes and Cube Roots

Maths worksheets lesson 59: Cubes and cube roots · Set 68 · 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 cube has a volume of 216 cubic cm. How long is each edge (in cm)?
  2. 2.A cube has a volume of 343 cubic cm. How long is each edge (in cm)?
  3. 3.What is ∛12167? =
  4. 4.Which of these is a perfect cube? (a) 730 (b) 807 (c) 729
  5. 5.What is the smallest whole number by which 24 must be multiplied to get a perfect cube?
  6. 6.What is 19³? =
  7. 7.What is ∛6859? =
  8. 8.Which of these is a perfect cube? (a) 64 (b) 65 (c) 101
  9. 9.A big cube of edge 5 cm is cut into small cubes of edge 1 cm. How many small cubes are there?
  10. 10.What is ∛9261? =
  11. 11.What is ∛1728? =
  12. 12.A cube has a volume of 64 cubic cm. How long is each edge (in cm)?
  13. 13.Which of these is a perfect cube? (a) 567 (b) 532 (c) 512
  14. 14.What is the smallest whole number by which 16 must be divided to get a perfect cube?
  15. 15.What is the smallest whole number by which 1944 must be multiplied to get a perfect cube?
  16. 16.A big cube of edge 18 cm is cut into small cubes of edge 3 cm. How many small cubes are there?
  17. 17.A big cube of edge 12 cm is cut into small cubes of edge 4 cm. How many small cubes are there?
  18. 18.What is ∛10648? =
  19. 19.What is 15³? =
  20. 20.A cube has a volume of 2197 cubic cm. How long is each edge (in cm)?
  21. 21.Which of these is a perfect cube? (a) 162 (b) 125 (c) 192
  22. 22.A big cube of edge 8 cm is cut into small cubes of edge 2 cm. How many small cubes are there?
  23. 23.What is 14³? =
  24. 24.What is ∛2744? =
  25. 25.A cube has a volume of 125 cubic cm. How long is each edge (in cm)?
  26. 26.What is the smallest whole number by which 9 must be divided to get a perfect cube?
  27. 27.What is ∛729? =
  28. 28.What is the smallest whole number by which 648 must be multiplied to get a perfect cube?
  29. 29.A cube has a volume of 6859 cubic cm. How long is each edge (in cm)?
  30. 30.What is the smallest whole number by which 875 must be multiplied to get a perfect cube?
  31. 31.A big cube of edge 2 cm is cut into small cubes of edge 1 cm. How many small cubes are there?
  32. 32.Which of these is a perfect cube? (a) 1255 (b) 1020 (c) 1000
  33. 33.A cube has a volume of 2744 cubic cm. How long is each edge (in cm)?
  34. 34.Which of these is a perfect cube? (a) 1331 (b) 1335 (c) 1516
  35. 35.What is ∛1331? =
  36. 36.Which of these is a perfect cube? (a) 388 (b) 427 (c) 343
  37. 37.Which of these is a perfect cube? (a) 2197 (b) 2697 (c) 2246
  38. 38.What is 12³? =
  39. 39.What is the smallest whole number by which 108 must be multiplied to get a perfect cube?
  40. 40.What is 18³? =

Answer key

  1. 6
  2. 7
  3. 23
  4. 729
  5. 9
  6. 6859
  7. 19
  8. 64
  9. 125
  10. 21
  11. 12
  12. 4
  13. 512
  14. 2
  15. 3
  16. 216
  17. 27
  18. 22
  19. 3375
  20. 13
  21. 125
  22. 64
  23. 2744
  24. 14
  25. 5
  26. 9
  27. 9
  28. 9
  29. 19
  30. 49
  31. 8
  32. 1000
  33. 14
  34. 1331
  35. 11
  36. 343
  37. 2197
  38. 1728
  39. 2
  40. 5832

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