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Class 8 Maths Worksheet: Cubes and Cube Roots

Maths worksheets lesson 59: Cubes and cube roots · Set 518 · 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 ∛6859? =
  2. 2.What is ∛125? =
  3. 3.Which of these is a perfect cube? (a) 1057 (b) 1000 (c) 1116
  4. 4.What is ∛8000? =
  5. 5.A cube has a volume of 8 cubic cm. How long is each edge (in cm)?
  6. 6.A cube has a volume of 343 cubic cm. How long is each edge (in cm)?
  7. 7.What is 6³? =
  8. 8.A cube has a volume of 64 cubic cm. How long is each edge (in cm)?
  9. 9.A big cube of edge 16 cm is cut into small cubes of edge 4 cm. How many small cubes are there?
  10. 10.What is 15³? =
  11. 11.What is ∛64? =
  12. 12.What is ∛10648? =
  13. 13.A big cube of edge 12 cm is cut into small cubes of edge 2 cm. How many small cubes are there?
  14. 14.What is ∛512? =
  15. 15.A cube has a volume of 2197 cubic cm. How long is each edge (in cm)?
  16. 16.A cube has a volume of 1331 cubic cm. How long is each edge (in cm)?
  17. 17.What is the smallest whole number by which 72 must be multiplied to get a perfect cube?
  18. 18.What is 12³? =
  19. 19.A cube has a volume of 729 cubic cm. How long is each edge (in cm)?
  20. 20.Which of these is a perfect cube? (a) 216 (b) 305 (c) 304
  21. 21.What is the smallest whole number by which 250 must be multiplied to get a perfect cube?
  22. 22.A big cube of edge 5 cm is cut into small cubes of edge 1 cm. How many small cubes are there?
  23. 23.What is ∛4096? =
  24. 24.What is ∛729? =
  25. 25.What is the smallest whole number by which 243 must be divided to get a perfect cube?
  26. 26.What is ∛5832? =
  27. 27.Which of these is a perfect cube? (a) 3039 (b) 3203 (c) 2744
  28. 28.A big cube of edge 6 cm is cut into small cubes of edge 1 cm. How many small cubes are there?
  29. 29.Which of these is a perfect cube? (a) 2014 (b) 1728 (c) 2073
  30. 30.A big cube of edge 20 cm is cut into small cubes of edge 4 cm. How many small cubes are there?
  31. 31.What is 13³? =
  32. 32.What is the smallest whole number by which 40 must be multiplied to get a perfect cube?
  33. 33.Which of these is a perfect cube? (a) 112 (b) 64 (c) 101
  34. 34.A cube has a volume of 1728 cubic cm. How long is each edge (in cm)?
  35. 35.What is the smallest whole number by which 24 must be divided to get a perfect cube?
  36. 36.Which of these is a perfect cube? (a) 27 (b) 34 (c) 45
  37. 37.Which of these is a perfect cube? (a) 677 (b) 578 (c) 512
  38. 38.What is the smallest whole number by which 25 must be multiplied to get a perfect cube?
  39. 39.Which of these is a perfect cube? (a) 1331 (b) 1384 (c) 1477
  40. 40.A big cube of edge 15 cm is cut into small cubes of edge 3 cm. How many small cubes are there?

Answer key

  1. 19
  2. 5
  3. 1000
  4. 20
  5. 2
  6. 7
  7. 216
  8. 4
  9. 64
  10. 3375
  11. 4
  12. 22
  13. 216
  14. 8
  15. 13
  16. 11
  17. 3
  18. 1728
  19. 9
  20. 216
  21. 4
  22. 125
  23. 16
  24. 9
  25. 9
  26. 18
  27. 2744
  28. 216
  29. 1728
  30. 125
  31. 2197
  32. 25
  33. 64
  34. 12
  35. 3
  36. 27
  37. 512
  38. 5
  39. 1331
  40. 125

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