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Class 8 Maths Worksheet: Cubes and Cube Roots

Maths worksheets lesson 59: Cubes and cube roots · Set 941 · 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 the smallest whole number by which 49 must be multiplied to get a perfect cube?
  2. 2.What is 3³? =
  3. 3.What is ∛5832? =
  4. 4.What is ∛125? =
  5. 5.A cube has a volume of 2744 cubic cm. How long is each edge (in cm)?
  6. 6.Which of these is a perfect cube? (a) 1899 (b) 1728 (c) 1984
  7. 7.A cube has a volume of 3375 cubic cm. How long is each edge (in cm)?
  8. 8.A cube has a volume of 216 cubic cm. How long is each edge (in cm)?
  9. 9.What is 8³? =
  10. 10.What is 14³? =
  11. 11.A big cube of edge 8 cm is cut into small cubes of edge 2 cm. How many small cubes are there?
  12. 12.What is 5³? =
  13. 13.Which of these is a perfect cube? (a) 216 (b) 310 (c) 247
  14. 14.A cube has a volume of 8 cubic cm. How long is each edge (in cm)?
  15. 15.What is 9³? =
  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.Which of these is a perfect cube? (a) 343 (b) 397 (c) 462
  18. 18.What is 4³? =
  19. 19.A big cube of edge 4 cm is cut into small cubes of edge 2 cm. How many small cubes are there?
  20. 20.A big cube of edge 2 cm is cut into small cubes of edge 1 cm. How many small cubes are there?
  21. 21.Which of these is a perfect cube? (a) 64 (b) 108 (c) 89
  22. 22.What is the smallest whole number by which 448 must be multiplied to get a perfect cube?
  23. 23.A cube has a volume of 8000 cubic cm. How long is each edge (in cm)?
  24. 24.What is 20³? =
  25. 25.Which of these is a perfect cube? (a) 125 (b) 155 (c) 159
  26. 26.What is ∛15625? =
  27. 27.What is 15³? =
  28. 28.Which of these is a perfect cube? (a) 2266 (b) 2197 (c) 2468
  29. 29.A big cube of edge 12 cm is cut into small cubes of edge 4 cm. How many small cubes are there?
  30. 30.A cube has a volume of 729 cubic cm. How long is each edge (in cm)?
  31. 31.A cube has a volume of 27 cubic cm. How long is each edge (in cm)?
  32. 32.What is 16³? =
  33. 33.Which of these is a perfect cube? (a) 27 (b) 33 (c) 43
  34. 34.A cube has a volume of 6859 cubic cm. How long is each edge (in cm)?
  35. 35.A cube has a volume of 125 cubic cm. How long is each edge (in cm)?
  36. 36.What is ∛9261? =
  37. 37.What is the smallest whole number by which 432 must be divided to get a perfect cube?
  38. 38.What is 6³? =
  39. 39.A big cube of edge 3 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) 2852 (b) 2744 (c) 2909

Answer key

  1. 7
  2. 27
  3. 18
  4. 5
  5. 14
  6. 1728
  7. 15
  8. 6
  9. 512
  10. 2744
  11. 64
  12. 125
  13. 216
  14. 2
  15. 729
  16. 216
  17. 343
  18. 64
  19. 8
  20. 8
  21. 64
  22. 49
  23. 20
  24. 8000
  25. 125
  26. 25
  27. 3375
  28. 2197
  29. 27
  30. 9
  31. 3
  32. 4096
  33. 27
  34. 19
  35. 5
  36. 21
  37. 2
  38. 216
  39. 27
  40. 2744

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