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Class 8 Maths Worksheet: Squares and Square Roots

Maths worksheets lesson 58: Squares and square roots · Set 184 · 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 sum of the first 29 odd numbers (1 + 3 + 5 + …)?
  2. 2.What is the sum of the first 11 odd numbers (1 + 3 + 5 + …)?
  3. 3.What is 87²? =
  4. 4.What is √289? =
  5. 5.How many whole numbers lie between 31² and 32²?
  6. 6.What is the smallest whole number by which 50 must be multiplied to get a perfect square?
  7. 7.What is the sum of the first 23 odd numbers (1 + 3 + 5 + …)?
  8. 8.What is the smallest whole number by which 448 must be multiplied to get a perfect square?
  9. 9.How many whole numbers lie between 17² and 18²?
  10. 10.What is the sum of the first 26 odd numbers (1 + 3 + 5 + …)?
  11. 11.What is 17²? =
  12. 12.A square garden has an area of 2116 square m. How long is each side (in m)?
  13. 13.What is the sum of the first 14 odd numbers (1 + 3 + 5 + …)?
  14. 14.What is √9604? =
  15. 15.A square garden has an area of 3481 square m. How long is each side (in m)?
  16. 16.What is 58²? =
  17. 17.What is the smallest whole number by which 45 must be multiplied to get a perfect square?
  18. 18.What is the smallest whole number by which 20 must be multiplied to get a perfect square?
  19. 19.What is the smallest whole number by which 112 must be divided to get a perfect square?
  20. 20.What is the sum of the first 24 odd numbers (1 + 3 + 5 + …)?
  21. 21.What is √3600? =
  22. 22.Which of these is a perfect square? (a) 256 (b) 259 (c) 272
  23. 23.What is √4096? =
  24. 24.Which of these is a perfect square? (a) 196 (b) 216 (c) 211
  25. 25.What is the sum of the first 19 odd numbers (1 + 3 + 5 + …)?
  26. 26.What is 52²? =
  27. 27.What is 14²? =
  28. 28.What is the sum of the first 17 odd numbers (1 + 3 + 5 + …)?
  29. 29.How many whole numbers lie between 9² and 10²?
  30. 30.What is the sum of the first 10 odd numbers (1 + 3 + 5 + …)?
  31. 31.What is √6561? =
  32. 32.What is 36²? =
  33. 33.What is 45²? =
  34. 34.A square garden has an area of 2809 square m. How long is each side (in m)?
  35. 35.What is √1521? =
  36. 36.Which of these is a perfect square? (a) 1376 (b) 1398 (c) 1369
  37. 37.What is 38²? =
  38. 38.Which of these is a perfect square? (a) 900 (b) 905 (c) 947
  39. 39.What is √5329? =
  40. 40.What is 63²? =

Answer key

  1. 841
  2. 121
  3. 7569
  4. 17
  5. 62
  6. 2
  7. 529
  8. 7
  9. 34
  10. 676
  11. 289
  12. 46
  13. 196
  14. 98
  15. 59
  16. 3364
  17. 5
  18. 5
  19. 7
  20. 576
  21. 60
  22. 256
  23. 64
  24. 196
  25. 361
  26. 2704
  27. 196
  28. 289
  29. 18
  30. 100
  31. 81
  32. 1296
  33. 2025
  34. 53
  35. 39
  36. 1369
  37. 1444
  38. 900
  39. 73
  40. 3969

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