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Class 8 Maths Worksheet: Cubes and Cube Roots

Maths worksheets lesson 59: Cubes and cube roots · Set 130 · 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.A cube has a volume of 27 cubic cm. How long is each edge (in cm)?
  2. 2.What is 2³? =
  3. 3.Which of these is a perfect cube? (a) 1331 (b) 1671 (c) 1370
  4. 4.What is 11³? =
  5. 5.A cube has a volume of 8000 cubic cm. How long is each edge (in cm)?
  6. 6.A big cube of edge 10 cm is cut into small cubes of edge 2 cm. How many small cubes are there?
  7. 7.A cube has a volume of 512 cubic cm. How long is each edge (in cm)?
  8. 8.A cube has a volume of 6859 cubic cm. How long is each edge (in cm)?
  9. 9.A big cube of edge 12 cm is cut into small cubes of edge 4 cm. How many small cubes are there?
  10. 10.What is 16³? =
  11. 11.Which of these is a perfect cube? (a) 144 (b) 125 (c) 151
  12. 12.What is 10³? =
  13. 13.Which of these is a perfect cube? (a) 2744 (b) 2950 (c) 2875
  14. 14.What is ∛5832? =
  15. 15.What is ∛2744? =
  16. 16.What is the smallest whole number by which 1512 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.What is 12³? =
  19. 19.A cube has a volume of 1728 cubic cm. How long is each edge (in cm)?
  20. 20.What is the smallest whole number by which 3 must be multiplied to get a perfect cube?
  21. 21.What is ∛125? =
  22. 22.What is 7³? =
  23. 23.What is the smallest whole number by which 16 must be multiplied to get a perfect cube?
  24. 24.Which of these is a perfect cube? (a) 1000 (b) 1137 (c) 1042
  25. 25.What is 19³? =
  26. 26.What is ∛4096? =
  27. 27.What is ∛343? =
  28. 28.What is ∛216? =
  29. 29.Which of these is a perfect cube? (a) 421 (b) 384 (c) 343
  30. 30.A big cube of edge 6 cm is cut into small cubes of edge 1 cm. How many small cubes are there?
  31. 31.A cube has a volume of 1331 cubic cm. How long is each edge (in cm)?
  32. 32.A big cube of edge 8 cm is cut into small cubes of edge 4 cm. How many small cubes are there?
  33. 33.A cube has a volume of 125 cubic cm. How long is each edge (in cm)?
  34. 34.What is ∛1000? =
  35. 35.Which of these is a perfect cube? (a) 251 (b) 269 (c) 216
  36. 36.What is ∛9261? =
  37. 37.What is the smallest whole number by which 1323 must be multiplied to get a perfect cube?
  38. 38.Which of these is a perfect cube? (a) 1728 (b) 1805 (c) 1770
  39. 39.Which of these is a perfect cube? (a) 729 (b) 777 (c) 960
  40. 40.What is the smallest whole number by which 128 must be multiplied to get a perfect cube?

Answer key

  1. 3
  2. 8
  3. 1331
  4. 1331
  5. 20
  6. 125
  7. 8
  8. 19
  9. 27
  10. 4096
  11. 125
  12. 1000
  13. 2744
  14. 18
  15. 14
  16. 49
  17. 125
  18. 1728
  19. 12
  20. 9
  21. 5
  22. 343
  23. 4
  24. 1000
  25. 6859
  26. 16
  27. 7
  28. 6
  29. 343
  30. 216
  31. 11
  32. 8
  33. 5
  34. 10
  35. 216
  36. 21
  37. 7
  38. 1728
  39. 729
  40. 4

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