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Class 8 Maths Worksheet: Cubes and Cube Roots

Maths worksheets lesson 59: Cubes and cube roots · Set 175 · 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.Which of these is a perfect cube? (a) 1063 (b) 1047 (c) 1000
  2. 2.Which of these is a perfect cube? (a) 2831 (b) 2744 (c) 2935
  3. 3.What is 4³? =
  4. 4.What is 7³? =
  5. 5.A big cube of edge 8 cm is cut into small cubes of edge 2 cm. How many small cubes are there?
  6. 6.What is the smallest whole number by which 2 must be multiplied to get a perfect cube?
  7. 7.A big cube of edge 5 cm is cut into small cubes of edge 1 cm. How many small cubes are there?
  8. 8.What is the smallest whole number by which 54 must be multiplied to get a perfect cube?
  9. 9.What is the smallest whole number by which 392 must be multiplied to get a perfect cube?
  10. 10.A big cube of edge 20 cm is cut into small cubes of edge 4 cm. How many small cubes are there?
  11. 11.What is 18³? =
  12. 12.What is ∛2197? =
  13. 13.What is ∛216? =
  14. 14.A cube has a volume of 512 cubic cm. How long is each edge (in cm)?
  15. 15.Which of these is a perfect cube? (a) 165 (b) 169 (c) 125
  16. 16.Which of these is a perfect cube? (a) 236 (b) 216 (c) 264
  17. 17.Which of these is a perfect cube? (a) 824 (b) 815 (c) 729
  18. 18.What is ∛9261? =
  19. 19.What is ∛125? =
  20. 20.What is ∛64? =
  21. 21.Which of these is a perfect cube? (a) 2054 (b) 1834 (c) 1728
  22. 22.What is ∛729? =
  23. 23.What is ∛343? =
  24. 24.A big cube of edge 2 cm is cut into small cubes of edge 1 cm. How many small cubes are there?
  25. 25.What is ∛4096? =
  26. 26.What is 20³? =
  27. 27.A cube has a volume of 216 cubic cm. How long is each edge (in cm)?
  28. 28.What is the smallest whole number by which 1512 must be multiplied to get a perfect cube?
  29. 29.A cube has a volume of 1728 cubic cm. How long is each edge (in cm)?
  30. 30.Which of these is a perfect cube? (a) 1331 (b) 1539 (c) 1664
  31. 31.What is 16³? =
  32. 32.What is the smallest whole number by which 4 must be multiplied to get a perfect cube?
  33. 33.Which of these is a perfect cube? (a) 94 (b) 64 (c) 70
  34. 34.What is the smallest whole number by which 2 must be divided to get a perfect cube?
  35. 35.What is ∛6859? =
  36. 36.A big cube of edge 15 cm is cut into small cubes of edge 3 cm. How many small cubes are there?
  37. 37.A cube has a volume of 8 cubic cm. How long is each edge (in cm)?
  38. 38.Which of these is a perfect cube? (a) 516 (b) 630 (c) 512
  39. 39.What is the smallest whole number by which 875 must be divided to get a perfect cube?
  40. 40.What is the smallest whole number by which 189 must be divided to get a perfect cube?

Answer key

  1. 1000
  2. 2744
  3. 64
  4. 343
  5. 64
  6. 4
  7. 125
  8. 4
  9. 7
  10. 125
  11. 5832
  12. 13
  13. 6
  14. 8
  15. 125
  16. 216
  17. 729
  18. 21
  19. 5
  20. 4
  21. 1728
  22. 9
  23. 7
  24. 8
  25. 16
  26. 8000
  27. 6
  28. 49
  29. 12
  30. 1331
  31. 4096
  32. 2
  33. 64
  34. 2
  35. 19
  36. 125
  37. 2
  38. 512
  39. 7
  40. 7

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