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Class 8 Maths Worksheet: Cubes and Cube Roots

Maths worksheets lesson 59: Cubes and cube roots · Set 458 · 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) 2744 (b) 3062 (c) 2839
  2. 2.What is the smallest whole number by which 1323 must be multiplied to get a perfect cube?
  3. 3.What is ∛216? =
  4. 4.A big cube of edge 8 cm is cut into small cubes of edge 4 cm. How many small cubes are there?
  5. 5.What is the smallest whole number by which 25 must be divided to get a perfect cube?
  6. 6.Which of these is a perfect cube? (a) 869 (b) 729 (c) 900
  7. 7.What is the smallest whole number by which 250 must be multiplied to get a perfect cube?
  8. 8.A big cube of edge 18 cm is cut into small cubes of edge 3 cm. How many small cubes are there?
  9. 9.What is ∛3375? =
  10. 10.Which of these is a perfect cube? (a) 216 (b) 221 (c) 247
  11. 11.A big cube of edge 5 cm is cut into small cubes of edge 1 cm. How many small cubes are there?
  12. 12.What is 5³? =
  13. 13.Which of these is a perfect cube? (a) 164 (b) 129 (c) 125
  14. 14.A big cube of edge 4 cm is cut into small cubes of edge 1 cm. How many small cubes are there?
  15. 15.What is the smallest whole number by which 32 must be divided to get a perfect cube?
  16. 16.What is 16³? =
  17. 17.Which of these is a perfect cube? (a) 3375 (b) 3753 (c) 3693
  18. 18.What is the smallest whole number by which 108 must be divided to get a perfect cube?
  19. 19.A big cube of edge 2 cm is cut into small cubes of edge 1 cm. How many small cubes are there?
  20. 20.What is 12³? =
  21. 21.What is 6³? =
  22. 22.A cube has a volume of 27 cubic cm. How long is each edge (in cm)?
  23. 23.What is ∛125? =
  24. 24.A big cube of edge 4 cm is cut into small cubes of edge 2 cm. How many small cubes are there?
  25. 25.What is the smallest whole number by which 72 must be divided to get a perfect cube?
  26. 26.What is 4³? =
  27. 27.A cube has a volume of 2744 cubic cm. How long is each edge (in cm)?
  28. 28.What is 15³? =
  29. 29.A cube has a volume of 125 cubic cm. How long is each edge (in cm)?
  30. 30.What is ∛8? =
  31. 31.What is the smallest whole number by which 875 must be divided to get a perfect cube?
  32. 32.A big cube of edge 6 cm is cut into small cubes of edge 1 cm. How many small cubes are there?
  33. 33.A cube has a volume of 1331 cubic cm. How long is each edge (in cm)?
  34. 34.A big cube of edge 3 cm is cut into small cubes of edge 1 cm. How many small cubes are there?
  35. 35.A big cube of edge 12 cm is cut into small cubes of edge 3 cm. How many small cubes are there?
  36. 36.Which of these is a perfect cube? (a) 1089 (b) 1000 (c) 1269
  37. 37.A cube has a volume of 4913 cubic cm. How long is each edge (in cm)?
  38. 38.What is ∛12167? =
  39. 39.What is 20³? =
  40. 40.Which of these is a perfect cube? (a) 512 (b) 533 (c) 635

Answer key

  1. 2744
  2. 7
  3. 6
  4. 8
  5. 25
  6. 729
  7. 4
  8. 216
  9. 15
  10. 216
  11. 125
  12. 125
  13. 125
  14. 64
  15. 4
  16. 4096
  17. 3375
  18. 4
  19. 8
  20. 1728
  21. 216
  22. 3
  23. 5
  24. 8
  25. 9
  26. 64
  27. 14
  28. 3375
  29. 5
  30. 2
  31. 7
  32. 216
  33. 11
  34. 27
  35. 64
  36. 1000
  37. 17
  38. 23
  39. 8000
  40. 512

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