← Cubes and cube roots lesson New set →

Class 8 Maths Worksheet: Cubes and Cube Roots

Maths worksheets lesson 59: Cubes and cube roots · Set 805 · 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 ∛9261? =
  2. 2.What is 5³? =
  3. 3.What is ∛10648? =
  4. 4.A big cube of edge 12 cm is cut into small cubes of edge 3 cm. How many small cubes are there?
  5. 5.A cube has a volume of 2744 cubic cm. How long is each edge (in cm)?
  6. 6.What is 12³? =
  7. 7.Which of these is a perfect cube? (a) 42 (b) 41 (c) 27
  8. 8.What is ∛4096? =
  9. 9.A big cube of edge 8 cm is cut into small cubes of edge 2 cm. How many small cubes are there?
  10. 10.What is the smallest whole number by which 1512 must be multiplied to get a perfect cube?
  11. 11.What is the smallest whole number by which 864 must be multiplied to get a perfect cube?
  12. 12.Which of these is a perfect cube? (a) 146 (b) 152 (c) 125
  13. 13.What is ∛4913? =
  14. 14.What is the smallest whole number by which 1600 must be multiplied to get a perfect cube?
  15. 15.A big cube of edge 15 cm is cut into small cubes of edge 3 cm. How many small cubes are there?
  16. 16.A cube has a volume of 216 cubic cm. How long is each edge (in cm)?
  17. 17.What is the smallest whole number by which 3125 must be divided to get a perfect cube?
  18. 18.What is 16³? =
  19. 19.A big cube of edge 18 cm is cut into small cubes of edge 3 cm. How many small cubes are there?
  20. 20.What is 14³? =
  21. 21.What is ∛27? =
  22. 22.What is the smallest whole number by which 3136 must be divided to get a perfect cube?
  23. 23.A cube has a volume of 125 cubic cm. How long is each edge (in cm)?
  24. 24.What is ∛64? =
  25. 25.What is the smallest whole number by which 9 must be divided to get a perfect cube?
  26. 26.What is the smallest whole number by which 392 must be multiplied to get a perfect cube?
  27. 27.Which of these is a perfect cube? (a) 1331 (b) 1351 (c) 1489
  28. 28.Which of these is a perfect cube? (a) 78 (b) 64 (c) 91
  29. 29.A big cube of edge 20 cm is cut into small cubes of edge 4 cm. How many small cubes are there?
  30. 30.A cube has a volume of 729 cubic cm. How long is each edge (in cm)?
  31. 31.What is 20³? =
  32. 32.What is 2³? =
  33. 33.A cube has a volume of 64 cubic cm. How long is each edge (in cm)?
  34. 34.What is ∛512? =
  35. 35.What is ∛8? =
  36. 36.Which of these is a perfect cube? (a) 445 (b) 360 (c) 343
  37. 37.What is 18³? =
  38. 38.What is the smallest whole number by which 3136 must be multiplied to get a perfect cube?
  39. 39.What is ∛1000? =
  40. 40.What is ∛5832? =

Answer key

  1. 21
  2. 125
  3. 22
  4. 64
  5. 14
  6. 1728
  7. 27
  8. 16
  9. 64
  10. 49
  11. 2
  12. 125
  13. 17
  14. 5
  15. 125
  16. 6
  17. 25
  18. 4096
  19. 216
  20. 2744
  21. 3
  22. 49
  23. 5
  24. 4
  25. 9
  26. 7
  27. 1331
  28. 64
  29. 125
  30. 9
  31. 8000
  32. 8
  33. 4
  34. 8
  35. 2
  36. 343
  37. 5832
  38. 7
  39. 10
  40. 18

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