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Class 8 Maths Worksheet: Cubes and Cube Roots

Maths worksheets lesson 59: Cubes and cube roots · Set 998 · 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 14³? =
  2. 2.What is ∛125? =
  3. 3.Which of these is a perfect cube? (a) 851 (b) 729 (c) 748
  4. 4.What is ∛4913? =
  5. 5.What is ∛27? =
  6. 6.A big cube of edge 4 cm is cut into small cubes of edge 1 cm. How many small cubes are there?
  7. 7.A cube has a volume of 4096 cubic cm. How long is each edge (in cm)?
  8. 8.What is ∛8? =
  9. 9.A big cube of edge 8 cm is cut into small cubes of edge 2 cm. How many small cubes are there?
  10. 10.What is ∛5832? =
  11. 11.A big cube of edge 18 cm is cut into small cubes of edge 3 cm. How many small cubes are there?
  12. 12.What is 20³? =
  13. 13.Which of these is a perfect cube? (a) 1613 (b) 1331 (c) 1453
  14. 14.A cube has a volume of 8 cubic cm. How long is each edge (in cm)?
  15. 15.What is ∛512? =
  16. 16.What is the smallest whole number by which 81 must be divided to get a perfect cube?
  17. 17.What is ∛15625? =
  18. 18.A big cube of edge 12 cm is cut into small cubes of edge 3 cm. How many small cubes are there?
  19. 19.What is 15³? =
  20. 20.Which of these is a perfect cube? (a) 1854 (b) 1728 (c) 1747
  21. 21.What is 9³? =
  22. 22.Which of these is a perfect cube? (a) 35 (b) 27 (c) 53
  23. 23.A big cube of edge 16 cm is cut into small cubes of edge 4 cm. How many small cubes are there?
  24. 24.What is ∛6859? =
  25. 25.What is the smallest whole number by which 40 must be multiplied to get a perfect cube?
  26. 26.What is the smallest whole number by which 72 must be divided to get a perfect cube?
  27. 27.A cube has a volume of 8000 cubic cm. How long is each edge (in cm)?
  28. 28.What is ∛13824? =
  29. 29.A cube has a volume of 729 cubic cm. How long is each edge (in cm)?
  30. 30.Which of these is a perfect cube? (a) 147 (b) 125 (c) 177
  31. 31.What is the smallest whole number by which 2 must be divided to get a perfect cube?
  32. 32.What is 8³? =
  33. 33.A cube has a volume of 5832 cubic cm. How long is each edge (in cm)?
  34. 34.What is 6³? =
  35. 35.A big cube of edge 10 cm is cut into small cubes of edge 2 cm. How many small cubes are there?
  36. 36.What is 10³? =
  37. 37.What is ∛1331? =
  38. 38.Which of these is a perfect cube? (a) 4027 (b) 3606 (c) 3375
  39. 39.What is the smallest whole number by which 6125 must be divided to get a perfect cube?
  40. 40.What is the smallest whole number by which 3 must be divided to get a perfect cube?

Answer key

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

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