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Class 8 Maths Worksheet: Squares and Square Roots

Maths worksheets lesson 58: Squares and square roots · Set 486 · 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 9 odd numbers (1 + 3 + 5 + …)?
  2. 2.A square garden has an area of 729 square m. How long is each side (in m)?
  3. 3.Which of these is a perfect square? (a) 1538 (b) 1521 (c) 1592
  4. 4.How many whole numbers lie between 34² and 35²?
  5. 5.What is √2704? =
  6. 6.What is the sum of the first 8 odd numbers (1 + 3 + 5 + …)?
  7. 7.What is 15²? =
  8. 8.What is the smallest whole number by which 896 must be multiplied to get a perfect square?
  9. 9.Which of these is a perfect square? (a) 496 (b) 484 (c) 494
  10. 10.What is the smallest whole number by which 150 must be divided to get a perfect square?
  11. 11.What is the sum of the first 14 odd numbers (1 + 3 + 5 + …)?
  12. 12.What is the smallest whole number by which 80 must be divided to get a perfect square?
  13. 13.How many whole numbers lie between 21² and 22²?
  14. 14.What is the smallest whole number by which 50 must be divided to get a perfect square?
  15. 15.What is 20²? =
  16. 16.What is the smallest whole number by which 1053 must be multiplied to get a perfect square?
  17. 17.What is √7569? =
  18. 18.What is the sum of the first 11 odd numbers (1 + 3 + 5 + …)?
  19. 19.What is the sum of the first 6 odd numbers (1 + 3 + 5 + …)?
  20. 20.Which of these is a perfect square? (a) 174 (b) 169 (c) 178
  21. 21.What is √1225? =
  22. 22.Which of these is a perfect square? (a) 225 (b) 235 (c) 247
  23. 23.What is √529? =
  24. 24.How many whole numbers lie between 18² and 19²?
  25. 25.A square garden has an area of 49 square m. How long is each side (in m)?
  26. 26.What is √2916? =
  27. 27.What is √8281? =
  28. 28.A square garden has an area of 2500 square m. How long is each side (in m)?
  29. 29.What is the sum of the first 21 odd numbers (1 + 3 + 5 + …)?
  30. 30.What is √9604? =
  31. 31.What is the smallest whole number by which 176 must be multiplied to get a perfect square?
  32. 32.What is the smallest whole number by which 325 must be multiplied to get a perfect square?
  33. 33.What is 45²? =
  34. 34.What is the sum of the first 5 odd numbers (1 + 3 + 5 + …)?
  35. 35.What is the sum of the first 10 odd numbers (1 + 3 + 5 + …)?
  36. 36.What is √3600? =
  37. 37.Which of these is a perfect square? (a) 209 (b) 196 (c) 199
  38. 38.What is the sum of the first 19 odd numbers (1 + 3 + 5 + …)?
  39. 39.What is the smallest whole number by which 350 must be multiplied to get a perfect square?
  40. 40.What is the smallest whole number by which 275 must be multiplied to get a perfect square?

Answer key

  1. 81
  2. 27
  3. 1521
  4. 68
  5. 52
  6. 64
  7. 225
  8. 14
  9. 484
  10. 6
  11. 196
  12. 5
  13. 42
  14. 2
  15. 400
  16. 13
  17. 87
  18. 121
  19. 36
  20. 169
  21. 35
  22. 225
  23. 23
  24. 36
  25. 7
  26. 54
  27. 91
  28. 50
  29. 441
  30. 98
  31. 11
  32. 13
  33. 2025
  34. 25
  35. 100
  36. 60
  37. 196
  38. 361
  39. 14
  40. 11

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