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Class 8 Maths Worksheet: Cubes and Cube Roots

Maths worksheets lesson 59: Cubes and cube roots · Set 103 · 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 6 cm is cut into small cubes of edge 2 cm. How many small cubes are there?
  2. 2.What is ∛8000? =
  3. 3.A big cube of edge 6 cm is cut into small cubes of edge 1 cm. How many small cubes are there?
  4. 4.What is 4³? =
  5. 5.Which of these is a perfect cube? (a) 77 (b) 87 (c) 64
  6. 6.What is the smallest whole number by which 3136 must be divided to get a perfect cube?
  7. 7.What is 6³? =
  8. 8.Which of these is a perfect cube? (a) 1331 (b) 1502 (c) 1475
  9. 9.What is 12³? =
  10. 10.A cube has a volume of 125 cubic cm. How long is each edge (in cm)?
  11. 11.A cube has a volume of 2197 cubic cm. How long is each edge (in cm)?
  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) 1232 (b) 1222 (c) 1000
  14. 14.What is 8³? =
  15. 15.What is ∛5832? =
  16. 16.What is 13³? =
  17. 17.What is ∛6859? =
  18. 18.A cube has a volume of 216 cubic cm. How long is each edge (in cm)?
  19. 19.What is the smallest whole number by which 5400 must be multiplied to get a perfect cube?
  20. 20.A cube has a volume of 4913 cubic cm. How long is each edge (in cm)?
  21. 21.What is ∛13824? =
  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.A big cube of edge 6 cm is cut into small cubes of edge 3 cm. How many small cubes are there?
  24. 24.What is 11³? =
  25. 25.What is 10³? =
  26. 26.Which of these is a perfect cube? (a) 2092 (b) 1728 (c) 2120
  27. 27.Which of these is a perfect cube? (a) 4038 (b) 3375 (c) 3928
  28. 28.A cube has a volume of 4096 cubic cm. How long is each edge (in cm)?
  29. 29.What is ∛729? =
  30. 30.What is 5³? =
  31. 31.What is 16³? =
  32. 32.What is the smallest whole number by which 24 must be divided to get a perfect cube?
  33. 33.What is ∛15625? =
  34. 34.What is 7³? =
  35. 35.What is the smallest whole number by which 648 must be divided to get a perfect cube?
  36. 36.What is ∛64? =
  37. 37.What is the smallest whole number by which 56 must be divided to get a perfect cube?
  38. 38.What is 3³? =
  39. 39.A big cube of edge 4 cm is cut into small cubes of edge 1 cm. How many small cubes are there?
  40. 40.What is 9³? =

Answer key

  1. 27
  2. 20
  3. 216
  4. 64
  5. 64
  6. 49
  7. 216
  8. 1331
  9. 1728
  10. 5
  11. 13
  12. 4
  13. 1000
  14. 512
  15. 18
  16. 2197
  17. 19
  18. 6
  19. 5
  20. 17
  21. 24
  22. 64
  23. 8
  24. 1331
  25. 1000
  26. 1728
  27. 3375
  28. 16
  29. 9
  30. 125
  31. 4096
  32. 3
  33. 25
  34. 343
  35. 3
  36. 4
  37. 7
  38. 27
  39. 64
  40. 729

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