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Class 8 Maths Worksheet: Squares and Square Roots

Maths worksheets lesson 58: Squares and square roots · Set 391 · 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.How many whole numbers lie between 7² and 8²?
  2. 2.What is 62²? =
  3. 3.A square garden has an area of 256 square m. How long is each side (in m)?
  4. 4.How many whole numbers lie between 13² and 14²?
  5. 5.What is √2209? =
  6. 6.What is 21²? =
  7. 7.Which of these is a perfect square? (a) 1054 (b) 1067 (c) 1024
  8. 8.What is 72²? =
  9. 9.What is the sum of the first 13 odd numbers (1 + 3 + 5 + …)?
  10. 10.What is 40²? =
  11. 11.What is 34²? =
  12. 12.What is 73²? =
  13. 13.Which of these is a perfect square? (a) 821 (b) 794 (c) 784
  14. 14.What is 71²? =
  15. 15.What is the smallest whole number by which 98 must be divided to get a perfect square?
  16. 16.A square garden has an area of 2304 square m. How long is each side (in m)?
  17. 17.What is the sum of the first 5 odd numbers (1 + 3 + 5 + …)?
  18. 18.What is √625? =
  19. 19.How many whole numbers lie between 22² and 23²?
  20. 20.How many whole numbers lie between 11² and 12²?
  21. 21.Which of these is a perfect square? (a) 1444 (b) 1504 (c) 1512
  22. 22.What is the sum of the first 11 odd numbers (1 + 3 + 5 + …)?
  23. 23.What is 47²? =
  24. 24.A square garden has an area of 576 square m. How long is each side (in m)?
  25. 25.What is √1156? =
  26. 26.What is the sum of the first 16 odd numbers (1 + 3 + 5 + …)?
  27. 27.What is the smallest whole number by which 135 must be divided to get a perfect square?
  28. 28.What is the sum of the first 30 odd numbers (1 + 3 + 5 + …)?
  29. 29.What is 64²? =
  30. 30.What is √8836? =
  31. 31.What is √289? =
  32. 32.What is √7921? =
  33. 33.How many whole numbers lie between 34² and 35²?
  34. 34.Which of these is a perfect square? (a) 342 (b) 324 (c) 328
  35. 35.Which of these is a perfect square? (a) 428 (b) 408 (c) 400
  36. 36.What is the sum of the first 8 odd numbers (1 + 3 + 5 + …)?
  37. 37.A square garden has an area of 1681 square m. How long is each side (in m)?
  38. 38.How many whole numbers lie between 49² and 50²?
  39. 39.What is the sum of the first 12 odd numbers (1 + 3 + 5 + …)?
  40. 40.What is the sum of the first 17 odd numbers (1 + 3 + 5 + …)?

Answer key

  1. 14
  2. 3844
  3. 16
  4. 26
  5. 47
  6. 441
  7. 1024
  8. 5184
  9. 169
  10. 1600
  11. 1156
  12. 5329
  13. 784
  14. 5041
  15. 2
  16. 48
  17. 25
  18. 25
  19. 44
  20. 22
  21. 1444
  22. 121
  23. 2209
  24. 24
  25. 34
  26. 256
  27. 15
  28. 900
  29. 4096
  30. 94
  31. 17
  32. 89
  33. 68
  34. 324
  35. 400
  36. 64
  37. 41
  38. 98
  39. 144
  40. 289

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