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Class 8 Maths Worksheet: Squares and Square Roots

Maths worksheets lesson 58: Squares and square roots · Set 714 · 40 sums
TalentJR

The method (Pairs make squares): Square: n × n. Quick way: (a + b)² = a² + 2ab + b², e.g. 42² = 1600 + 160 + 4. Square root: the number that times itself gives the square; a square ending in 4 has a root ending in 2 or 8. Make a perfect square: break into primes; multiply (or divide) by the prime left without a partner. 1 + 3 + 5 + … (n odd numbers) = n². Between n² and (n + 1)² there are 2n whole numbers.

NameDateTime takenScore ___ / 40
  1. 1.What is 17²? =
  2. 2.What is the smallest whole number by which 832 must be multiplied to get a perfect square?
  3. 3.What is the sum of the first 29 odd numbers (1 + 3 + 5 + …)?
  4. 4.What is the smallest whole number by which 1134 must be multiplied to get a perfect square?
  5. 5.Which of these is a perfect square? (a) 339 (b) 324 (c) 330
  6. 6.What is the sum of the first 12 odd numbers (1 + 3 + 5 + …)?
  7. 7.A square garden has an area of 961 square m. How long is each side (in m)?
  8. 8.What is √400? =
  9. 9.What is the smallest whole number by which 250 must be multiplied to get a perfect square?
  10. 10.A square garden has an area of 36 square m. How long is each side (in m)?
  11. 11.What is the sum of the first 7 odd numbers (1 + 3 + 5 + …)?
  12. 12.What is the smallest whole number by which 96 must be multiplied to get a perfect square?
  13. 13.What is √625? =
  14. 14.What is the smallest whole number by which 810 must be multiplied to get a perfect square?
  15. 15.What is √784? =
  16. 16.What is 12²? =
  17. 17.Which of these is a perfect square? (a) 132 (b) 130 (c) 121
  18. 18.What is 54²? =
  19. 19.Which of these is a perfect square? (a) 171 (b) 175 (c) 169
  20. 20.What is the smallest whole number by which 275 must be multiplied to get a perfect square?
  21. 21.A square garden has an area of 169 square m. How long is each side (in m)?
  22. 22.How many whole numbers lie between 29² and 30²?
  23. 23.What is 51²? =
  24. 24.How many whole numbers lie between 31² and 32²?
  25. 25.A square garden has an area of 784 square m. How long is each side (in m)?
  26. 26.What is the sum of the first 26 odd numbers (1 + 3 + 5 + …)?
  27. 27.What is the sum of the first 21 odd numbers (1 + 3 + 5 + …)?
  28. 28.Which of these is a perfect square? (a) 720 (b) 727 (c) 676
  29. 29.A square garden has an area of 400 square m. How long is each side (in m)?
  30. 30.What is 98²? =
  31. 31.What is the smallest whole number by which 350 must be divided to get a perfect square?
  32. 32.How many whole numbers lie between 44² and 45²?
  33. 33.What is the smallest whole number by which 20 must be multiplied to get a perfect square?
  34. 34.What is 45²? =
  35. 35.What is the smallest whole number by which 640 must be divided to get a perfect square?
  36. 36.What is 65²? =
  37. 37.How many whole numbers lie between 16² and 17²?
  38. 38.Which of these is a perfect square? (a) 734 (b) 729 (c) 735
  39. 39.What is the smallest whole number by which 350 must be multiplied to get a perfect square?
  40. 40.What is the smallest whole number by which 325 must be multiplied to get a perfect square?

Answer key

  1. 289
  2. 13
  3. 841
  4. 14
  5. 324
  6. 144
  7. 31
  8. 20
  9. 10
  10. 6
  11. 49
  12. 6
  13. 25
  14. 10
  15. 28
  16. 144
  17. 121
  18. 2916
  19. 169
  20. 11
  21. 13
  22. 58
  23. 2601
  24. 62
  25. 28
  26. 676
  27. 441
  28. 676
  29. 20
  30. 9604
  31. 14
  32. 88
  33. 5
  34. 2025
  35. 10
  36. 4225
  37. 32
  38. 729
  39. 14
  40. 13

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