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Class 8 Maths Worksheet: Cubes and Cube Roots

Maths worksheets lesson 59: Cubes and cube roots · Set 414 · 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 8 cm is cut into small cubes of edge 2 cm. How many small cubes are there?
  2. 2.A cube has a volume of 343 cubic cm. How long is each edge (in cm)?
  3. 3.Which of these is a perfect cube? (a) 1331 (b) 1427 (c) 1686
  4. 4.What is 3³? =
  5. 5.Which of these is a perfect cube? (a) 1249 (b) 1145 (c) 1000
  6. 6.What is the smallest whole number by which 128 must be divided to get a perfect cube?
  7. 7.A cube has a volume of 512 cubic cm. How long is each edge (in cm)?
  8. 8.What is ∛125? =
  9. 9.What is the smallest whole number by which 200 must be divided to get a perfect cube?
  10. 10.A big cube of edge 18 cm is cut into small cubes of edge 3 cm. How many small cubes are there?
  11. 11.Which of these is a perfect cube? (a) 1920 (b) 1761 (c) 1728
  12. 12.What is 12³? =
  13. 13.Which of these is a perfect cube? (a) 829 (b) 869 (c) 729
  14. 14.What is 17³? =
  15. 15.A big cube of edge 6 cm is cut into small cubes of edge 1 cm. How many small cubes are there?
  16. 16.A big cube of edge 8 cm is cut into small cubes of edge 4 cm. How many small cubes are there?
  17. 17.What is the smallest whole number by which 375 must be divided to get a perfect cube?
  18. 18.A cube has a volume of 125 cubic cm. How long is each edge (in cm)?
  19. 19.What is ∛2744? =
  20. 20.What is ∛13824? =
  21. 21.What is ∛15625? =
  22. 22.Which of these is a perfect cube? (a) 125 (b) 191 (c) 127
  23. 23.What is ∛729? =
  24. 24.What is ∛1331? =
  25. 25.What is 2³? =
  26. 26.What is ∛5832? =
  27. 27.What is 13³? =
  28. 28.What is ∛27? =
  29. 29.Which of these is a perfect cube? (a) 39 (b) 27 (c) 40
  30. 30.What is 4³? =
  31. 31.A big cube of edge 3 cm is cut into small cubes of edge 1 cm. How many small cubes are there?
  32. 32.What is the smallest whole number by which 1323 must be divided to get a perfect cube?
  33. 33.What is the smallest whole number by which 1512 must be divided to get a perfect cube?
  34. 34.A big cube of edge 4 cm is cut into small cubes of edge 2 cm. How many small cubes are there?
  35. 35.What is ∛12167? =
  36. 36.What is the smallest whole number by which 648 must be divided to get a perfect cube?
  37. 37.What is the smallest whole number by which 250 must be multiplied to get a perfect cube?
  38. 38.What is ∛3375? =
  39. 39.A big cube of edge 2 cm is cut into small cubes of edge 1 cm. How many small cubes are there?
  40. 40.Which of these is a perfect cube? (a) 236 (b) 244 (c) 216

Answer key

  1. 64
  2. 7
  3. 1331
  4. 27
  5. 1000
  6. 2
  7. 8
  8. 5
  9. 25
  10. 216
  11. 1728
  12. 1728
  13. 729
  14. 4913
  15. 216
  16. 8
  17. 3
  18. 5
  19. 14
  20. 24
  21. 25
  22. 125
  23. 9
  24. 11
  25. 8
  26. 18
  27. 2197
  28. 3
  29. 27
  30. 64
  31. 27
  32. 49
  33. 7
  34. 8
  35. 23
  36. 3
  37. 4
  38. 15
  39. 8
  40. 216

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