← Cubes and cube roots lesson New set →

Class 8 Maths Worksheet: Cubes and Cube Roots

Maths worksheets lesson 59: Cubes and cube roots · Set 635 · 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) 47 (b) 27 (c) 34
  2. 2.Which of these is a perfect cube? (a) 1728 (b) 2145 (c) 1799
  3. 3.What is ∛1331? =
  4. 4.A cube has a volume of 1331 cubic cm. How long is each edge (in cm)?
  5. 5.What is ∛512? =
  6. 6.What is 19³? =
  7. 7.What is the smallest whole number by which 256 must be multiplied to get a perfect cube?
  8. 8.A cube has a volume of 2197 cubic cm. How long is each edge (in cm)?
  9. 9.A cube has a volume of 125 cubic cm. How long is each edge (in cm)?
  10. 10.What is 17³? =
  11. 11.What is ∛3375? =
  12. 12.A cube has a volume of 5832 cubic cm. How long is each edge (in cm)?
  13. 13.What is 3³? =
  14. 14.What is the smallest whole number by which 1080 must be multiplied to get a perfect cube?
  15. 15.A big cube of edge 18 cm is cut into small cubes of edge 3 cm. How many small cubes are there?
  16. 16.Which of these is a perfect cube? (a) 628 (b) 512 (c) 629
  17. 17.A cube has a volume of 64 cubic cm. How long is each edge (in cm)?
  18. 18.What is 11³? =
  19. 19.A cube has a volume of 8000 cubic cm. How long is each edge (in cm)?
  20. 20.What is 16³? =
  21. 21.What is ∛13824? =
  22. 22.A cube has a volume of 27 cubic cm. How long is each edge (in cm)?
  23. 23.A big cube of edge 6 cm is cut into small cubes of edge 3 cm. How many small cubes are there?
  24. 24.Which of these is a perfect cube? (a) 438 (b) 406 (c) 343
  25. 25.A big cube of edge 3 cm is cut into small cubes of edge 1 cm. How many small cubes are there?
  26. 26.A big cube of edge 2 cm is cut into small cubes of edge 1 cm. How many small cubes are there?
  27. 27.A big cube of edge 4 cm is cut into small cubes of edge 2 cm. How many small cubes are there?
  28. 28.What is the smallest whole number by which 432 must be divided to get a perfect cube?
  29. 29.A cube has a volume of 343 cubic cm. How long is each edge (in cm)?
  30. 30.What is ∛729? =
  31. 31.What is the smallest whole number by which 81 must be multiplied to get a perfect cube?
  32. 32.What is 9³? =
  33. 33.What is ∛125? =
  34. 34.What is 6³? =
  35. 35.What is the smallest whole number by which 5 must be divided to get a perfect cube?
  36. 36.A cube has a volume of 216 cubic cm. How long is each edge (in cm)?
  37. 37.What is the smallest whole number by which 5 must be multiplied to get a perfect cube?
  38. 38.Which of these is a perfect cube? (a) 729 (b) 820 (c) 756
  39. 39.What is ∛64? =
  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. 27
  2. 1728
  3. 11
  4. 11
  5. 8
  6. 6859
  7. 2
  8. 13
  9. 5
  10. 4913
  11. 15
  12. 18
  13. 27
  14. 25
  15. 216
  16. 512
  17. 4
  18. 1331
  19. 20
  20. 4096
  21. 24
  22. 3
  23. 8
  24. 343
  25. 27
  26. 8
  27. 8
  28. 2
  29. 7
  30. 9
  31. 9
  32. 729
  33. 5
  34. 216
  35. 5
  36. 6
  37. 25
  38. 729
  39. 4
  40. 125

Free maths worksheets lessons, practice and worksheets at talentjr.in/maths-worksheets