← Cubes and cube roots lesson New set →

Class 8 Maths Worksheet: Cubes and Cube Roots

Maths worksheets lesson 59: Cubes and cube roots · Set 301 · 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 ∛343? =
  2. 2.What is the smallest whole number by which 81 must be multiplied to get a perfect cube?
  3. 3.What is ∛8000? =
  4. 4.A big cube of edge 8 cm is cut into small cubes of edge 2 cm. How many small cubes are there?
  5. 5.Which of these is a perfect cube? (a) 155 (b) 125 (c) 147
  6. 6.What is ∛2197? =
  7. 7.Which of these is a perfect cube? (a) 1032 (b) 1208 (c) 1000
  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.A cube has a volume of 216 cubic cm. How long is each edge (in cm)?
  10. 10.What is 18³? =
  11. 11.What is ∛1331? =
  12. 12.A cube has a volume of 512 cubic cm. How long is each edge (in cm)?
  13. 13.What is the smallest whole number by which 9 must be multiplied to get a perfect cube?
  14. 14.A cube has a volume of 8000 cubic cm. How long is each edge (in cm)?
  15. 15.A big cube of edge 5 cm is cut into small cubes of edge 1 cm. How many small cubes are there?
  16. 16.What is ∛2744? =
  17. 17.A big cube of edge 12 cm is cut into small cubes of edge 3 cm. How many small cubes are there?
  18. 18.What is the smallest whole number by which 5 must be multiplied to get a perfect cube?
  19. 19.What is the smallest whole number by which 648 must be multiplied to get a perfect cube?
  20. 20.What is 13³? =
  21. 21.What is ∛10648? =
  22. 22.What is the smallest whole number by which 648 must be divided to get a perfect cube?
  23. 23.What is 14³? =
  24. 24.A cube has a volume of 1728 cubic cm. How long is each edge (in cm)?
  25. 25.What is 4³? =
  26. 26.What is ∛64? =
  27. 27.What is 9³? =
  28. 28.What is 11³? =
  29. 29.A big cube of edge 3 cm is cut into small cubes of edge 1 cm. How many small cubes are there?
  30. 30.A big cube of edge 9 cm is cut into small cubes of edge 3 cm. How many small cubes are there?
  31. 31.What is the smallest whole number by which 250 must be divided to get a perfect cube?
  32. 32.A big cube of edge 24 cm is cut into small cubes of edge 4 cm. How many small cubes are there?
  33. 33.What is the smallest whole number by which 1125 must be divided to get a perfect cube?
  34. 34.What is the smallest whole number by which 56 must be divided to get a perfect cube?
  35. 35.A cube has a volume of 5832 cubic cm. How long is each edge (in cm)?
  36. 36.A big cube of edge 2 cm is cut into small cubes of edge 1 cm. How many small cubes are there?
  37. 37.What is the smallest whole number by which 25 must be divided to get a perfect cube?
  38. 38.What is ∛9261? =
  39. 39.What is the smallest whole number by which 54 must be multiplied to get a perfect cube?
  40. 40.A cube has a volume of 343 cubic cm. How long is each edge (in cm)?

Answer key

  1. 7
  2. 9
  3. 20
  4. 64
  5. 125
  6. 13
  7. 1000
  8. 216
  9. 6
  10. 5832
  11. 11
  12. 8
  13. 3
  14. 20
  15. 125
  16. 14
  17. 64
  18. 25
  19. 9
  20. 2197
  21. 22
  22. 3
  23. 2744
  24. 12
  25. 64
  26. 4
  27. 729
  28. 1331
  29. 27
  30. 27
  31. 2
  32. 216
  33. 9
  34. 7
  35. 18
  36. 8
  37. 25
  38. 21
  39. 4
  40. 7

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