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Estimating Square Roots and Division Worksheet

Mental maths lesson 27: Estimate divisions and square roots · Set 284 · 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.√37 to 1 decimal place? (a) 6.0 (b) 6.3 (c) 6.1 (d) 6.2
  2. 2.√78 to 1 decimal place? (a) 8.7 (b) 9.0 (c) 8.8 (d) 8.9
  3. 3.√26 to 1 decimal place? (a) 5.3 (b) 5.2 (c) 5.1 (d) 5.4
  4. 4.√56 to 1 decimal place? (a) 7.6 (b) 7.5 (c) 7.4 (d) 7.7
  5. 5.√63 to 1 decimal place? (a) 7.9 (b) 8.1 (c) 7.8 (d) 8.0
  6. 6.Best estimate of 1147 ÷ 44? (a) 290 (b) 2900 (c) 29
  7. 7.Best estimate of 4119 ÷ 71? (a) 5900 (b) 59 (c) 590
  8. 8.Best estimate of 2891 ÷ 32? (a) 960 (b) 9600 (c) 96
  9. 9.Best estimate of 3641 ÷ 39? (a) 91 (b) 9100 (c) 910
  10. 10.√34 to 1 decimal place? (a) 5.9 (b) 5.8 (c) 6.0 (d) 5.7
  11. 11.√84 to 1 decimal place? (a) 9.2 (b) 9.1 (c) 9.4 (d) 9.3
  12. 12.Best estimate of 4689 ÷ 56? (a) 780 (b) 7800 (c) 78
  13. 13.Best estimate of 6564 ÷ 83? (a) 8200 (b) 82 (c) 820
  14. 14.√58 to 1 decimal place? (a) 7.5 (b) 7.7 (c) 7.8 (d) 7.6
  15. 15.√96 to 1 decimal place? (a) 9.8 (b) 10.1 (c) 9.9 (d) 10.0
  16. 16.Best estimate of 2111 ÷ 38? (a) 5300 (b) 53 (c) 530
  17. 17.√61 to 1 decimal place? (a) 7.9 (b) 8.1 (c) 7.8 (d) 8.0
  18. 18.√40 to 1 decimal place? (a) 6.3 (b) 6.2 (c) 6.4 (d) 6.5
  19. 19.Best estimate of 3220 ÷ 62? (a) 540 (b) 54 (c) 5400
  20. 20.Best estimate of 2029 ÷ 28? (a) 68 (b) 6800 (c) 680
  21. 21.√43 to 1 decimal place? (a) 6.8 (b) 6.9 (c) 6.6 (d) 6.7
  22. 22.Best estimate of 1953 ÷ 47? (a) 390 (b) 3900 (c) 39
  23. 23.Best estimate of 7663 ÷ 82? (a) 96 (b) 9600 (c) 960
  24. 24.√69 to 1 decimal place? (a) 8.4 (b) 8.1 (c) 8.2 (d) 8.3
  25. 25.Best estimate of 669 ÷ 31? (a) 22 (b) 2200 (c) 220
  26. 26.Best estimate of 1307 ÷ 42? (a) 330 (b) 3300 (c) 33
  27. 27.Best estimate of 2777 ÷ 77? (a) 3500 (b) 350 (c) 35
  28. 28.Best estimate of 1727 ÷ 62? (a) 290 (b) 2900 (c) 29
  29. 29.Best estimate of 493 ÷ 32? (a) 160 (b) 1600 (c) 16
  30. 30.√74 to 1 decimal place? (a) 8.5 (b) 8.7 (c) 8.8 (d) 8.6
  31. 31.√41 to 1 decimal place? (a) 6.3 (b) 6.4 (c) 6.5 (d) 6.6
  32. 32.Best estimate of 2962 ÷ 37? (a) 7400 (b) 740 (c) 74
  33. 33.√32 to 1 decimal place? (a) 5.5 (b) 5.6 (c) 5.4 (d) 5.7
  34. 34.Best estimate of 6444 ÷ 68? (a) 92 (b) 9200 (c) 920
  35. 35.Best estimate of 2836 ÷ 32? (a) 9500 (b) 950 (c) 95
  36. 36.Best estimate of 4046 ÷ 46? (a) 8100 (b) 81 (c) 810
  37. 37.√29 to 1 decimal place? (a) 5.4 (b) 5.1 (c) 5.2 (d) 5.3
  38. 38.Best estimate of 1508 ÷ 32? (a) 500 (b) 50 (c) 5000
  39. 39.Best estimate of 1684 ÷ 78? (a) 21 (b) 2100 (c) 210
  40. 40.Best estimate of 1108 ÷ 34? (a) 37 (b) 3700 (c) 370

Answer key

  1. 6.1
  2. 8.8
  3. 5.1
  4. 7.5
  5. 7.9
  6. 29
  7. 59
  8. 96
  9. 91
  10. 5.8
  11. 9.2
  12. 78
  13. 82
  14. 7.6
  15. 9.8
  16. 53
  17. 7.8
  18. 6.3
  19. 54
  20. 68
  21. 6.6
  22. 39
  23. 96
  24. 8.3
  25. 22
  26. 33
  27. 35
  28. 29
  29. 16
  30. 8.6
  31. 6.4
  32. 74
  33. 5.7
  34. 92
  35. 95
  36. 81
  37. 5.4
  38. 50
  39. 21
  40. 37

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