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Class 8 Maths Worksheet: Squares and Square Roots

Maths worksheets lesson 58: Squares and square roots · Set 661 · 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 637 must be divided to get a perfect square?
  2. 2.What is 16²? =
  3. 3.What is the sum of the first 28 odd numbers (1 + 3 + 5 + …)?
  4. 4.What is the smallest whole number by which 350 must be multiplied to get a perfect square?
  5. 5.A square garden has an area of 324 square m. How long is each side (in m)?
  6. 6.What is 31²? =
  7. 7.What is √144? =
  8. 8.What is 38²? =
  9. 9.What is √2209? =
  10. 10.A square garden has an area of 1849 square m. How long is each side (in m)?
  11. 11.What is the sum of the first 30 odd numbers (1 + 3 + 5 + …)?
  12. 12.What is √289? =
  13. 13.A square garden has an area of 3136 square m. How long is each side (in m)?
  14. 14.What is the sum of the first 25 odd numbers (1 + 3 + 5 + …)?
  15. 15.What is the sum of the first 6 odd numbers (1 + 3 + 5 + …)?
  16. 16.Which of these is a perfect square? (a) 532 (b) 570 (c) 529
  17. 17.Which of these is a perfect square? (a) 1401 (b) 1420 (c) 1369
  18. 18.Which of these is a perfect square? (a) 922 (b) 900 (c) 935
  19. 19.How many whole numbers lie between 10² and 11²?
  20. 20.What is the smallest whole number by which 8 must be multiplied to get a perfect square?
  21. 21.What is √9025? =
  22. 22.What is 56²? =
  23. 23.Which of these is a perfect square? (a) 100 (b) 120 (c) 106
  24. 24.What is the smallest whole number by which 27 must be multiplied to get a perfect square?
  25. 25.What is the sum of the first 10 odd numbers (1 + 3 + 5 + …)?
  26. 26.What is the smallest whole number by which 735 must be divided to get a perfect square?
  27. 27.What is 54²? =
  28. 28.How many whole numbers lie between 13² and 14²?
  29. 29.How many whole numbers lie between 27² and 28²?
  30. 30.A square garden has an area of 3025 square m. How long is each side (in m)?
  31. 31.How many whole numbers lie between 7² and 8²?
  32. 32.What is the sum of the first 27 odd numbers (1 + 3 + 5 + …)?
  33. 33.What is the smallest whole number by which 128 must be divided to get a perfect square?
  34. 34.What is √3721? =
  35. 35.Which of these is a perfect square? (a) 625 (b) 631 (c) 663
  36. 36.What is 17²? =
  37. 37.What is the smallest whole number by which 54 must be divided to get a perfect square?
  38. 38.What is √3025? =
  39. 39.What is the smallest whole number by which 405 must be divided to get a perfect square?
  40. 40.What is √6084? =

Answer key

  1. 13
  2. 256
  3. 784
  4. 14
  5. 18
  6. 961
  7. 12
  8. 1444
  9. 47
  10. 43
  11. 900
  12. 17
  13. 56
  14. 625
  15. 36
  16. 529
  17. 1369
  18. 900
  19. 20
  20. 2
  21. 95
  22. 3136
  23. 100
  24. 3
  25. 100
  26. 15
  27. 2916
  28. 26
  29. 54
  30. 55
  31. 14
  32. 729
  33. 2
  34. 61
  35. 625
  36. 289
  37. 6
  38. 55
  39. 5
  40. 78

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