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Class 8 Maths Worksheet: Squares and Square Roots

Maths worksheets lesson 58: Squares and square roots · Set 703 · 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 53²? =
  2. 2.What is the sum of the first 28 odd numbers (1 + 3 + 5 + …)?
  3. 3.What is the smallest whole number by which 117 must be divided to get a perfect square?
  4. 4.What is the sum of the first 20 odd numbers (1 + 3 + 5 + …)?
  5. 5.What is 18²? =
  6. 6.What is the smallest whole number by which 40 must be divided to get a perfect square?
  7. 7.What is 67²? =
  8. 8.What is 46²? =
  9. 9.What is the smallest whole number by which 539 must be divided to get a perfect square?
  10. 10.What is 45²? =
  11. 11.Which of these is a perfect square? (a) 1369 (b) 1403 (c) 1436
  12. 12.What is the smallest whole number by which 375 must be multiplied to get a perfect square?
  13. 13.A square garden has an area of 144 square m. How long is each side (in m)?
  14. 14.Which of these is a perfect square? (a) 225 (b) 249 (c) 243
  15. 15.What is the sum of the first 7 odd numbers (1 + 3 + 5 + …)?
  16. 16.What is 30²? =
  17. 17.What is 89²? =
  18. 18.What is √9216? =
  19. 19.What is 14²? =
  20. 20.Which of these is a perfect square? (a) 148 (b) 164 (c) 144
  21. 21.Which of these is a perfect square? (a) 961 (b) 1019 (c) 1014
  22. 22.What is √121? =
  23. 23.What is the smallest whole number by which 112 must be divided to get a perfect square?
  24. 24.A square garden has an area of 1849 square m. How long is each side (in m)?
  25. 25.Which of these is a perfect square? (a) 175 (b) 185 (c) 169
  26. 26.What is √2025? =
  27. 27.What is √1225? =
  28. 28.How many whole numbers lie between 30² and 31²?
  29. 29.What is 68²? =
  30. 30.What is the sum of the first 23 odd numbers (1 + 3 + 5 + …)?
  31. 31.What is √4356? =
  32. 32.What is the smallest whole number by which 50 must be multiplied to get a perfect square?
  33. 33.How many whole numbers lie between 44² and 45²?
  34. 34.What is the smallest whole number by which 48 must be multiplied to get a perfect square?
  35. 35.What is the smallest whole number by which 147 must be divided to get a perfect square?
  36. 36.What is √4900? =
  37. 37.What is 13²? =
  38. 38.How many whole numbers lie between 18² and 19²?
  39. 39.What is the sum of the first 5 odd numbers (1 + 3 + 5 + …)?
  40. 40.Which of these is a perfect square? (a) 587 (b) 588 (c) 576

Answer key

  1. 2809
  2. 784
  3. 13
  4. 400
  5. 324
  6. 10
  7. 4489
  8. 2116
  9. 11
  10. 2025
  11. 1369
  12. 15
  13. 12
  14. 225
  15. 49
  16. 900
  17. 7921
  18. 96
  19. 196
  20. 144
  21. 961
  22. 11
  23. 7
  24. 43
  25. 169
  26. 45
  27. 35
  28. 60
  29. 4624
  30. 529
  31. 66
  32. 2
  33. 88
  34. 3
  35. 3
  36. 70
  37. 169
  38. 36
  39. 25
  40. 576

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