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Class 8 Maths Worksheet: Squares and Square Roots

Maths worksheets lesson 58: Squares and square roots · Set 500 · 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 the smallest whole number by which 50 must be multiplied to get a perfect square?
  2. 2.What is √1089? =
  3. 3.What is the sum of the first 26 odd numbers (1 + 3 + 5 + …)?
  4. 4.How many whole numbers lie between 28² and 29²?
  5. 5.What is 78²? =
  6. 6.What is 91²? =
  7. 7.What is √6561? =
  8. 8.What is the sum of the first 30 odd numbers (1 + 3 + 5 + …)?
  9. 9.What is 94²? =
  10. 10.What is the smallest whole number by which 45 must be divided to get a perfect square?
  11. 11.How many whole numbers lie between 20² and 21²?
  12. 12.A square garden has an area of 3600 square m. How long is each side (in m)?
  13. 13.How many whole numbers lie between 37² and 38²?
  14. 14.How many whole numbers lie between 35² and 36²?
  15. 15.How many whole numbers lie between 12² and 13²?
  16. 16.What is the smallest whole number by which 384 must be divided to get a perfect square?
  17. 17.What is 52²? =
  18. 18.What is the smallest whole number by which 175 must be multiplied to get a perfect square?
  19. 19.What is √256? =
  20. 20.Which of these is a perfect square? (a) 282 (b) 256 (c) 273
  21. 21.What is the sum of the first 14 odd numbers (1 + 3 + 5 + …)?
  22. 22.What is the sum of the first 25 odd numbers (1 + 3 + 5 + …)?
  23. 23.What is √729? =
  24. 24.A square garden has an area of 400 square m. How long is each side (in m)?
  25. 25.How many whole numbers lie between 13² and 14²?
  26. 26.What is 18²? =
  27. 27.What is 72²? =
  28. 28.What is the smallest whole number by which 375 must be multiplied to get a perfect square?
  29. 29.What is 75²? =
  30. 30.A square garden has an area of 1521 square m. How long is each side (in m)?
  31. 31.What is 88²? =
  32. 32.What is 25²? =
  33. 33.What is √3136? =
  34. 34.What is 30²? =
  35. 35.What is the sum of the first 12 odd numbers (1 + 3 + 5 + …)?
  36. 36.What is √676? =
  37. 37.What is 22²? =
  38. 38.What is the sum of the first 13 odd numbers (1 + 3 + 5 + …)?
  39. 39.A square garden has an area of 841 square m. How long is each side (in m)?
  40. 40.What is √4489? =

Answer key

  1. 2
  2. 33
  3. 676
  4. 56
  5. 6084
  6. 8281
  7. 81
  8. 900
  9. 8836
  10. 5
  11. 40
  12. 60
  13. 74
  14. 70
  15. 24
  16. 6
  17. 2704
  18. 7
  19. 16
  20. 256
  21. 196
  22. 625
  23. 27
  24. 20
  25. 26
  26. 324
  27. 5184
  28. 15
  29. 5625
  30. 39
  31. 7744
  32. 625
  33. 56
  34. 900
  35. 144
  36. 26
  37. 484
  38. 169
  39. 29
  40. 67

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