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Class 8 Maths Worksheet: Cubes and Cube Roots

Maths worksheets lesson 59: Cubes and cube roots · Set 679 · 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 1944 must be multiplied to get a perfect cube?
  2. 2.What is the smallest whole number by which 7 must be divided to get a perfect cube?
  3. 3.Which of these is a perfect cube? (a) 106 (b) 66 (c) 64
  4. 4.What is 11³? =
  5. 5.A big cube of edge 6 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 1512 must be multiplied to get a perfect cube?
  7. 7.What is 9³? =
  8. 8.What is ∛13824? =
  9. 9.What is the smallest whole number by which 320 must be multiplied to get a perfect cube?
  10. 10.What is ∛10648? =
  11. 11.A big cube of edge 16 cm is cut into small cubes of edge 4 cm. How many small cubes are there?
  12. 12.What is the smallest whole number by which 5 must be divided to get a perfect cube?
  13. 13.What is the smallest whole number by which 1080 must be divided to get a perfect cube?
  14. 14.A cube has a volume of 2744 cubic cm. How long is each edge (in cm)?
  15. 15.A cube has a volume of 27 cubic cm. How long is each edge (in cm)?
  16. 16.What is the smallest whole number by which 24 must be multiplied to get a perfect cube?
  17. 17.A big cube of edge 15 cm is cut into small cubes of edge 3 cm. How many small cubes are there?
  18. 18.Which of these is a perfect cube? (a) 3375 (b) 4026 (c) 3751
  19. 19.Which of these is a perfect cube? (a) 2052 (b) 1731 (c) 1728
  20. 20.What is 10³? =
  21. 21.A cube has a volume of 343 cubic cm. How long is each edge (in cm)?
  22. 22.What is 19³? =
  23. 23.A cube has a volume of 64 cubic cm. How long is each edge (in cm)?
  24. 24.What is 5³? =
  25. 25.What is ∛1331? =
  26. 26.What is ∛343? =
  27. 27.What is the smallest whole number by which 24 must be divided to get a perfect cube?
  28. 28.What is ∛12167? =
  29. 29.What is 18³? =
  30. 30.What is the smallest whole number by which 7 must be multiplied to get a perfect cube?
  31. 31.A big cube of edge 12 cm is cut into small cubes of edge 2 cm. How many small cubes are there?
  32. 32.What is 6³? =
  33. 33.What is ∛5832? =
  34. 34.What is 13³? =
  35. 35.What is 4³? =
  36. 36.A big cube of edge 8 cm is cut into small cubes of edge 4 cm. How many small cubes are there?
  37. 37.Which of these is a perfect cube? (a) 1331 (b) 1390 (c) 1506
  38. 38.Which of these is a perfect cube? (a) 27 (b) 44 (c) 30
  39. 39.Which of these is a perfect cube? (a) 250 (b) 233 (c) 216
  40. 40.A big cube of edge 20 cm is cut into small cubes of edge 4 cm. How many small cubes are there?

Answer key

  1. 3
  2. 7
  3. 64
  4. 1331
  5. 27
  6. 49
  7. 729
  8. 24
  9. 25
  10. 22
  11. 64
  12. 5
  13. 5
  14. 14
  15. 3
  16. 9
  17. 125
  18. 3375
  19. 1728
  20. 1000
  21. 7
  22. 6859
  23. 4
  24. 125
  25. 11
  26. 7
  27. 3
  28. 23
  29. 5832
  30. 49
  31. 216
  32. 216
  33. 18
  34. 2197
  35. 64
  36. 8
  37. 1331
  38. 27
  39. 216
  40. 125

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