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Estimating Square Roots and Division Worksheet

Mental maths lesson 27: Estimate divisions and square roots · Set 127 · 40 questions
TalentJR

How to do it in your head (Guess, divide, average): Division: round the divisor to the nearest ten and find the closest multiple of it. Square root: guess the nearest whole root, then divide the number by your guess. Average the guess and the answer of the division, and round to 1 decimal place.

NameDateTime takenScore ___ / 40
  1. 1.√84 to 1 decimal place? (a) 9.3 (b) 9.2 (c) 9.1 (d) 9.4
  2. 2.Best estimate of 2706 ÷ 86? (a) 300 (b) 3000 (c) 30
  3. 3.√52 to 1 decimal place? (a) 7.3 (b) 7.4 (c) 7.5 (d) 7.2
  4. 4.Best estimate of 3419 ÷ 63? (a) 570 (b) 5700 (c) 57
  5. 5.Best estimate of 2941 ÷ 68? (a) 4200 (b) 42 (c) 420
  6. 6.√98 to 1 decimal place? (a) 10.0 (b) 9.8 (c) 9.9 (d) 10.1
  7. 7.√43 to 1 decimal place? (a) 6.7 (b) 6.4 (c) 6.5 (d) 6.6
  8. 8.Best estimate of 1205 ÷ 69? (a) 170 (b) 1700 (c) 17
  9. 9.Best estimate of 1318 ÷ 49? (a) 260 (b) 2600 (c) 26
  10. 10.√66 to 1 decimal place? (a) 8.0 (b) 8.2 (c) 8.1 (d) 8.3
  11. 11.√74 to 1 decimal place? (a) 8.6 (b) 8.5 (c) 8.8 (d) 8.7
  12. 12.Best estimate of 5297 ÷ 61? (a) 8800 (b) 88 (c) 880
  13. 13.√40 to 1 decimal place? (a) 6.1 (b) 6.2 (c) 6.0 (d) 6.3
  14. 14.Best estimate of 2262 ÷ 46? (a) 45 (b) 450 (c) 4500
  15. 15.Best estimate of 3879 ÷ 63? (a) 650 (b) 6500 (c) 65
  16. 16.√50 to 1 decimal place? (a) 7.1 (b) 7.3 (c) 7.2 (d) 7.4
  17. 17.Best estimate of 1026 ÷ 57? (a) 170 (b) 1700 (c) 17
  18. 18.Best estimate of 4504 ÷ 52? (a) 9000 (b) 90 (c) 900
  19. 19.Best estimate of 2460 ÷ 51? (a) 49 (b) 490 (c) 4900
  20. 20.Best estimate of 1747 ÷ 26? (a) 580 (b) 58 (c) 5800
  21. 21.√94 to 1 decimal place? (a) 9.8 (b) 9.7 (c) 9.6 (d) 9.5
  22. 22.√96 to 1 decimal place? (a) 9.6 (b) 9.9 (c) 9.8 (d) 9.7
  23. 23.Best estimate of 7101 ÷ 81? (a) 8900 (b) 890 (c) 89
  24. 24.√26 to 1 decimal place? (a) 5.4 (b) 5.1 (c) 5.3 (d) 5.2
  25. 25.Best estimate of 2509 ÷ 58? (a) 4200 (b) 420 (c) 42
  26. 26.Best estimate of 1649 ÷ 52? (a) 330 (b) 33 (c) 3300
  27. 27.Best estimate of 870 ÷ 24? (a) 440 (b) 4400 (c) 44
  28. 28.Best estimate of 6542 ÷ 82? (a) 82 (b) 8200 (c) 820
  29. 29.√86 to 1 decimal place? (a) 9.3 (b) 9.5 (c) 9.4 (d) 9.2
  30. 30.Best estimate of 4287 ÷ 57? (a) 7100 (b) 71 (c) 710
  31. 31.Best estimate of 2366 ÷ 33? (a) 790 (b) 7900 (c) 79
  32. 32.√37 to 1 decimal place? (a) 6.0 (b) 5.8 (c) 5.9 (d) 6.1
  33. 33.√51 to 1 decimal place? (a) 7.1 (b) 6.8 (c) 6.9 (d) 7.0
  34. 34.√34 to 1 decimal place? (a) 5.7 (b) 5.6 (c) 5.9 (d) 5.8
  35. 35.Best estimate of 1811 ÷ 59? (a) 300 (b) 3000 (c) 30
  36. 36.Best estimate of 3376 ÷ 41? (a) 84 (b) 8400 (c) 840
  37. 37.√42 to 1 decimal place? (a) 6.5 (b) 6.6 (c) 6.8 (d) 6.7
  38. 38.√92 to 1 decimal place? (a) 9.3 (b) 9.6 (c) 9.5 (d) 9.4
  39. 39.Best estimate of 3479 ÷ 73? (a) 500 (b) 5000 (c) 50
  40. 40.√59 to 1 decimal place? (a) 8.0 (b) 7.7 (c) 7.9 (d) 7.8

Answer key

  1. 9.2
  2. 30
  3. 7.2
  4. 57
  5. 42
  6. 9.9
  7. 6.6
  8. 17
  9. 26
  10. 8.1
  11. 8.6
  12. 88
  13. 6.3
  14. 45
  15. 65
  16. 7.1
  17. 17
  18. 90
  19. 49
  20. 58
  21. 9.7
  22. 9.8
  23. 89
  24. 5.1
  25. 42
  26. 33
  27. 44
  28. 82
  29. 9.3
  30. 71
  31. 79
  32. 6.1
  33. 7.1
  34. 5.8
  35. 30
  36. 84
  37. 6.5
  38. 9.6
  39. 50
  40. 7.7

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