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Class 8 Maths Worksheet: Cubes and Cube Roots

Maths worksheets lesson 59: Cubes and cube roots · Set 534 · 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 ∛15625? =
  2. 2.Which of these is a perfect cube? (a) 3905 (b) 3375 (c) 4045
  3. 3.A cube has a volume of 343 cubic cm. How long is each edge (in cm)?
  4. 4.Which of these is a perfect cube? (a) 3164 (b) 2744 (c) 3252
  5. 5.What is ∛8? =
  6. 6.A big cube of edge 20 cm is cut into small cubes of edge 4 cm. How many small cubes are there?
  7. 7.What is the smallest whole number by which 243 must be multiplied to get a perfect cube?
  8. 8.A big cube of edge 12 cm is cut into small cubes of edge 2 cm. How many small cubes are there?
  9. 9.What is 4³? =
  10. 10.Which of these is a perfect cube? (a) 1728 (b) 1863 (c) 1924
  11. 11.What is the smallest whole number by which 256 must be divided to get a perfect cube?
  12. 12.A big cube of edge 9 cm is cut into small cubes of edge 3 cm. How many small cubes are there?
  13. 13.What is 10³? =
  14. 14.Which of these is a perfect cube? (a) 82 (b) 64 (c) 104
  15. 15.What is 20³? =
  16. 16.What is 3³? =
  17. 17.A big cube of edge 3 cm is cut into small cubes of edge 1 cm. How many small cubes are there?
  18. 18.What is the smallest whole number by which 192 must be divided to get a perfect cube?
  19. 19.Which of these is a perfect cube? (a) 1679 (b) 1533 (c) 1331
  20. 20.What is the smallest whole number by which 648 must be multiplied to get a perfect cube?
  21. 21.What is ∛2197? =
  22. 22.Which of these is a perfect cube? (a) 1000 (b) 1029 (c) 1082
  23. 23.What is ∛512? =
  24. 24.What is the smallest whole number by which 189 must be multiplied to get a perfect cube?
  25. 25.What is ∛1331? =
  26. 26.A big cube of edge 5 cm is cut into small cubes of edge 1 cm. How many small cubes are there?
  27. 27.A cube has a volume of 5832 cubic cm. How long is each edge (in cm)?
  28. 28.A big cube of edge 4 cm is cut into small cubes of edge 2 cm. How many small cubes are there?
  29. 29.What is 14³? =
  30. 30.What is 5³? =
  31. 31.A big cube of edge 12 cm is cut into small cubes of edge 3 cm. How many small cubes are there?
  32. 32.A cube has a volume of 8000 cubic cm. How long is each edge (in cm)?
  33. 33.What is 19³? =
  34. 34.A big cube of edge 6 cm is cut into small cubes of edge 2 cm. How many small cubes are there?
  35. 35.What is the smallest whole number by which 648 must be divided to get a perfect cube?
  36. 36.Which of these is a perfect cube? (a) 729 (b) 950 (c) 904
  37. 37.What is ∛3375? =
  38. 38.What is ∛343? =
  39. 39.What is 16³? =
  40. 40.What is the smallest whole number by which 9 must be divided to get a perfect cube?

Answer key

  1. 25
  2. 3375
  3. 7
  4. 2744
  5. 2
  6. 125
  7. 3
  8. 216
  9. 64
  10. 1728
  11. 4
  12. 27
  13. 1000
  14. 64
  15. 8000
  16. 27
  17. 27
  18. 3
  19. 1331
  20. 9
  21. 13
  22. 1000
  23. 8
  24. 49
  25. 11
  26. 125
  27. 18
  28. 8
  29. 2744
  30. 125
  31. 64
  32. 20
  33. 6859
  34. 27
  35. 3
  36. 729
  37. 15
  38. 7
  39. 4096
  40. 9

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