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Class 8 Maths Worksheet: Cubes and Cube Roots

Maths worksheets lesson 59: Cubes and cube roots · Set 404 · 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 10 cm is cut into small cubes of edge 2 cm. How many small cubes are there?
  2. 2.What is 3³? =
  3. 3.What is 13³? =
  4. 4.What is ∛729? =
  5. 5.Which of these is a perfect cube? (a) 170 (b) 173 (c) 125
  6. 6.Which of these is a perfect cube? (a) 27 (b) 41 (c) 36
  7. 7.What is ∛216? =
  8. 8.What is the smallest whole number by which 16 must be divided to get a perfect cube?
  9. 9.Which of these is a perfect cube? (a) 1284 (b) 1000 (c) 1032
  10. 10.A big cube of edge 8 cm is cut into small cubes of edge 2 cm. How many small cubes are there?
  11. 11.What is the smallest whole number by which 648 must be multiplied to get a perfect cube?
  12. 12.What is ∛343? =
  13. 13.What is the smallest whole number by which 40 must be divided to get a perfect cube?
  14. 14.A big cube of edge 18 cm is cut into small cubes of edge 3 cm. How many small cubes are there?
  15. 15.What is 15³? =
  16. 16.What is 4³? =
  17. 17.What is the smallest whole number by which 3125 must be multiplied to get a perfect cube?
  18. 18.What is 19³? =
  19. 19.What is 10³? =
  20. 20.Which of these is a perfect cube? (a) 69 (b) 77 (c) 64
  21. 21.A cube has a volume of 4096 cubic cm. How long is each edge (in cm)?
  22. 22.What is ∛10648? =
  23. 23.Which of these is a perfect cube? (a) 512 (b) 572 (c) 551
  24. 24.Which of these is a perfect cube? (a) 729 (b) 755 (c) 805
  25. 25.A cube has a volume of 27 cubic cm. How long is each edge (in cm)?
  26. 26.A cube has a volume of 6859 cubic cm. How long is each edge (in cm)?
  27. 27.What is 2³? =
  28. 28.Which of these is a perfect cube? (a) 2197 (b) 2216 (c) 2300
  29. 29.A cube has a volume of 2744 cubic cm. How long is each edge (in cm)?
  30. 30.What is 11³? =
  31. 31.What is ∛4913? =
  32. 32.A big cube of edge 15 cm is cut into small cubes of edge 3 cm. How many small cubes are there?
  33. 33.What is 6³? =
  34. 34.What is 14³? =
  35. 35.What is the smallest whole number by which 243 must be divided to get a perfect cube?
  36. 36.What is the smallest whole number by which 25 must be divided to get a perfect cube?
  37. 37.What is ∛27? =
  38. 38.What is the smallest whole number by which 10584 must be divided to get a perfect cube?
  39. 39.What is the smallest whole number by which 625 must be divided to get a perfect cube?
  40. 40.A big cube of edge 6 cm is cut into small cubes of edge 3 cm. How many small cubes are there?

Answer key

  1. 125
  2. 27
  3. 2197
  4. 9
  5. 125
  6. 27
  7. 6
  8. 2
  9. 1000
  10. 64
  11. 9
  12. 7
  13. 5
  14. 216
  15. 3375
  16. 64
  17. 5
  18. 6859
  19. 1000
  20. 64
  21. 16
  22. 22
  23. 512
  24. 729
  25. 3
  26. 19
  27. 8
  28. 2197
  29. 14
  30. 1331
  31. 17
  32. 125
  33. 216
  34. 2744
  35. 9
  36. 25
  37. 3
  38. 49
  39. 5
  40. 8

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