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Class 8 Maths Worksheet: Cubes and Cube Roots

Maths worksheets lesson 59: Cubes and cube roots · Set 531 · 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 243 must be multiplied to get a perfect cube?
  2. 2.Which of these is a perfect cube? (a) 30 (b) 43 (c) 27
  3. 3.What is ∛2744? =
  4. 4.What is the smallest whole number by which 1944 must be multiplied to get a perfect cube?
  5. 5.A cube has a volume of 512 cubic cm. How long is each edge (in cm)?
  6. 6.What is 13³? =
  7. 7.What is 14³? =
  8. 8.Which of these is a perfect cube? (a) 538 (b) 653 (c) 512
  9. 9.A cube has a volume of 343 cubic cm. How long is each edge (in cm)?
  10. 10.What is the smallest whole number by which 108 must be multiplied to get a perfect cube?
  11. 11.A cube has a volume of 64 cubic cm. How long is each edge (in cm)?
  12. 12.What is the smallest whole number by which 243 must be divided to get a perfect cube?
  13. 13.What is the smallest whole number by which 256 must be divided to get a perfect cube?
  14. 14.Which of these is a perfect cube? (a) 2558 (b) 2675 (c) 2197
  15. 15.What is ∛512? =
  16. 16.What is 8³? =
  17. 17.What is the smallest whole number by which 1600 must be multiplied to get a perfect cube?
  18. 18.Which of these is a perfect cube? (a) 1609 (b) 1331 (c) 1627
  19. 19.What is ∛9261? =
  20. 20.Which of these is a perfect cube? (a) 317 (b) 216 (c) 273
  21. 21.What is the smallest whole number by which 9 must be divided to get a perfect cube?
  22. 22.A big cube of edge 15 cm is cut into small cubes of edge 3 cm. How many small cubes are there?
  23. 23.Which of these is a perfect cube? (a) 94 (b) 64 (c) 65
  24. 24.What is ∛125? =
  25. 25.What is 18³? =
  26. 26.What is ∛1331? =
  27. 27.What is the smallest whole number by which 3136 must be divided to get a perfect cube?
  28. 28.A big cube of edge 24 cm is cut into small cubes of edge 4 cm. How many small cubes are there?
  29. 29.What is ∛13824? =
  30. 30.What is ∛216? =
  31. 31.A cube has a volume of 5832 cubic cm. How long is each edge (in cm)?
  32. 32.What is 7³? =
  33. 33.What is the smallest whole number by which 81 must be multiplied to get a perfect cube?
  34. 34.A big cube of edge 6 cm is cut into small cubes of edge 3 cm. How many small cubes are there?
  35. 35.A big cube of edge 8 cm is cut into small cubes of edge 4 cm. How many small cubes are there?
  36. 36.Which of these is a perfect cube? (a) 1000 (b) 1274 (c) 1057
  37. 37.What is 17³? =
  38. 38.What is the smallest whole number by which 40 must be multiplied to get a perfect cube?
  39. 39.What is ∛6859? =
  40. 40.A big cube of edge 4 cm is cut into small cubes of edge 1 cm. How many small cubes are there?

Answer key

  1. 3
  2. 27
  3. 14
  4. 3
  5. 8
  6. 2197
  7. 2744
  8. 512
  9. 7
  10. 2
  11. 4
  12. 9
  13. 4
  14. 2197
  15. 8
  16. 512
  17. 5
  18. 1331
  19. 21
  20. 216
  21. 9
  22. 125
  23. 64
  24. 5
  25. 5832
  26. 11
  27. 49
  28. 216
  29. 24
  30. 6
  31. 18
  32. 343
  33. 9
  34. 8
  35. 8
  36. 1000
  37. 4913
  38. 25
  39. 19
  40. 64

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