← Cubes and cube roots lesson New set →

Class 8 Maths Worksheet: Cubes and Cube Roots

Maths worksheets lesson 59: Cubes and cube roots · Set 700 · 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) 1000 (b) 1074 (c) 1086
  2. 2.A big cube of edge 3 cm is cut into small cubes of edge 1 cm. How many small cubes are there?
  3. 3.A big cube of edge 8 cm is cut into small cubes of edge 4 cm. How many small cubes are there?
  4. 4.What is ∛6859? =
  5. 5.A big cube of edge 9 cm is cut into small cubes of edge 3 cm. How many small cubes are there?
  6. 6.What is the smallest whole number by which 9 must be divided to get a perfect cube?
  7. 7.What is 17³? =
  8. 8.Which of these is a perfect cube? (a) 3375 (b) 3465 (c) 3485
  9. 9.What is 15³? =
  10. 10.What is 14³? =
  11. 11.What is 9³? =
  12. 12.What is 18³? =
  13. 13.What is ∛2744? =
  14. 14.What is ∛729? =
  15. 15.Which of these is a perfect cube? (a) 156 (b) 125 (c) 164
  16. 16.What is ∛1331? =
  17. 17.What is the smallest whole number by which 500 must be divided to get a perfect cube?
  18. 18.What is the smallest whole number by which 3125 must be divided to get a perfect cube?
  19. 19.What is ∛2197? =
  20. 20.What is ∛4913? =
  21. 21.What is the smallest whole number by which 4 must be multiplied to get a perfect cube?
  22. 22.Which of these is a perfect cube? (a) 49 (b) 27 (c) 31
  23. 23.Which of these is a perfect cube? (a) 453 (b) 367 (c) 343
  24. 24.What is the smallest whole number by which 25 must be multiplied to get a perfect cube?
  25. 25.What is 8³? =
  26. 26.A big cube of edge 4 cm is cut into small cubes of edge 1 cm. How many small cubes are there?
  27. 27.What is the smallest whole number by which 3136 must be multiplied to get a perfect cube?
  28. 28.Which of these is a perfect cube? (a) 66 (b) 108 (c) 64
  29. 29.A big cube of edge 12 cm is cut into small cubes of edge 3 cm. How many small cubes are there?
  30. 30.What is the smallest whole number by which 648 must be multiplied to get a perfect cube?
  31. 31.Which of these is a perfect cube? (a) 216 (b) 242 (c) 244
  32. 32.What is 3³? =
  33. 33.A cube has a volume of 4913 cubic cm. How long is each edge (in cm)?
  34. 34.What is 16³? =
  35. 35.What is the smallest whole number by which 25 must be divided to get a perfect cube?
  36. 36.What is the smallest whole number by which 72 must be multiplied to get a perfect cube?
  37. 37.A big cube of edge 6 cm is cut into small cubes of edge 1 cm. How many small cubes are there?
  38. 38.What is ∛27? =
  39. 39.What is ∛1000? =
  40. 40.A cube has a volume of 6859 cubic cm. How long is each edge (in cm)?

Answer key

  1. 1000
  2. 27
  3. 8
  4. 19
  5. 27
  6. 9
  7. 4913
  8. 3375
  9. 3375
  10. 2744
  11. 729
  12. 5832
  13. 14
  14. 9
  15. 125
  16. 11
  17. 4
  18. 25
  19. 13
  20. 17
  21. 2
  22. 27
  23. 343
  24. 5
  25. 512
  26. 64
  27. 7
  28. 64
  29. 64
  30. 9
  31. 216
  32. 27
  33. 17
  34. 4096
  35. 25
  36. 3
  37. 216
  38. 3
  39. 10
  40. 19

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