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Class 8 Maths Worksheet: Cubes and Cube Roots

Maths worksheets lesson 59: Cubes and cube roots · Set 519 · 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 20³? =
  2. 2.A big cube of edge 3 cm is cut into small cubes of edge 1 cm. How many small cubes are there?
  3. 3.A big cube of edge 6 cm is cut into small cubes of edge 2 cm. How many small cubes are there?
  4. 4.What is the smallest whole number by which 81 must be multiplied to get a perfect cube?
  5. 5.What is the smallest whole number by which 250 must be divided to get a perfect cube?
  6. 6.A big cube of edge 4 cm is cut into small cubes of edge 1 cm. How many small cubes are there?
  7. 7.Which of these is a perfect cube? (a) 2220 (b) 2208 (c) 2197
  8. 8.What is ∛512? =
  9. 9.A cube has a volume of 2197 cubic cm. How long is each edge (in cm)?
  10. 10.What is the smallest whole number by which 4 must be multiplied to get a perfect cube?
  11. 11.What is ∛9261? =
  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 8³? =
  14. 14.What is ∛10648? =
  15. 15.Which of these is a perfect cube? (a) 2744 (b) 2848 (c) 3220
  16. 16.A cube has a volume of 8000 cubic cm. How long is each edge (in cm)?
  17. 17.A big cube of edge 12 cm is cut into small cubes of edge 4 cm. How many small cubes are there?
  18. 18.What is ∛3375? =
  19. 19.What is 6³? =
  20. 20.A big cube of edge 10 cm is cut into small cubes of edge 2 cm. How many small cubes are there?
  21. 21.A cube has a volume of 343 cubic cm. How long is each edge (in cm)?
  22. 22.Which of these is a perfect cube? (a) 68 (b) 79 (c) 64
  23. 23.A big cube of edge 2 cm is cut into small cubes of edge 1 cm. How many small cubes are there?
  24. 24.A big cube of edge 24 cm is cut into small cubes of edge 4 cm. How many small cubes are there?
  25. 25.A cube has a volume of 5832 cubic cm. How long is each edge (in cm)?
  26. 26.What is the smallest whole number by which 7 must be divided to get a perfect cube?
  27. 27.What is the smallest whole number by which 16 must be multiplied to get a perfect cube?
  28. 28.What is 16³? =
  29. 29.A cube has a volume of 1000 cubic cm. How long is each edge (in cm)?
  30. 30.What is the smallest whole number by which 320 must be divided to get a perfect cube?
  31. 31.A cube has a volume of 8 cubic cm. How long is each edge (in cm)?
  32. 32.What is ∛216? =
  33. 33.What is 18³? =
  34. 34.Which of these is a perfect cube? (a) 48 (b) 27 (c) 51
  35. 35.Which of these is a perfect cube? (a) 196 (b) 125 (c) 166
  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 big cube of edge 8 cm is cut into small cubes of edge 4 cm. How many small cubes are there?
  38. 38.Which of these is a perfect cube? (a) 1728 (b) 2022 (c) 1815
  39. 39.What is the smallest whole number by which 54 must be divided to get a perfect cube?
  40. 40.Which of these is a perfect cube? (a) 309 (b) 216 (c) 251

Answer key

  1. 8000
  2. 27
  3. 27
  4. 9
  5. 2
  6. 64
  7. 2197
  8. 8
  9. 13
  10. 2
  11. 21
  12. 27
  13. 512
  14. 22
  15. 2744
  16. 20
  17. 27
  18. 15
  19. 216
  20. 125
  21. 7
  22. 64
  23. 8
  24. 216
  25. 18
  26. 7
  27. 4
  28. 4096
  29. 10
  30. 5
  31. 2
  32. 6
  33. 5832
  34. 27
  35. 125
  36. 125
  37. 8
  38. 1728
  39. 2
  40. 216

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