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Estimating Square Roots and Division Worksheet

Mental maths lesson 27: Estimate divisions and square roots · Set 51 · 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.Best estimate of 2571 ÷ 27? (a) 860 (b) 8600 (c) 86
  2. 2.√34 to 1 decimal place? (a) 5.8 (b) 5.9 (c) 5.7 (d) 6.0
  3. 3.Best estimate of 954 ÷ 32? (a) 320 (b) 32 (c) 3200
  4. 4.√74 to 1 decimal place? (a) 8.7 (b) 8.6 (c) 8.9 (d) 8.8
  5. 5.Best estimate of 7564 ÷ 88? (a) 84 (b) 8400 (c) 840
  6. 6.Best estimate of 2601 ÷ 36? (a) 650 (b) 65 (c) 6500
  7. 7.Best estimate of 2227 ÷ 67? (a) 3200 (b) 32 (c) 320
  8. 8.√88 to 1 decimal place? (a) 9.6 (b) 9.4 (c) 9.7 (d) 9.5
  9. 9.Best estimate of 545 ÷ 24? (a) 27 (b) 2700 (c) 270
  10. 10.Best estimate of 526 ÷ 26? (a) 18 (b) 180 (c) 1800
  11. 11.√44 to 1 decimal place? (a) 6.5 (b) 6.4 (c) 6.3 (d) 6.6
  12. 12.Best estimate of 2525 ÷ 28? (a) 84 (b) 840 (c) 8400
  13. 13.√38 to 1 decimal place? (a) 6.3 (b) 6.1 (c) 6.4 (d) 6.2
  14. 14.Best estimate of 2675 ÷ 34? (a) 89 (b) 890 (c) 8900
  15. 15.Best estimate of 3292 ÷ 82? (a) 410 (b) 41 (c) 4100
  16. 16.√23 to 1 decimal place? (a) 4.9 (b) 4.7 (c) 4.6 (d) 4.8
  17. 17.√87 to 1 decimal place? (a) 9.1 (b) 9.2 (c) 9.0 (d) 9.3
  18. 18.√37 to 1 decimal place? (a) 6.1 (b) 6.0 (c) 5.9 (d) 6.2
  19. 19.√51 to 1 decimal place? (a) 7.0 (b) 6.9 (c) 6.8 (d) 7.1
  20. 20.Best estimate of 5256 ÷ 77? (a) 6600 (b) 660 (c) 66
  21. 21.Best estimate of 2510 ÷ 28? (a) 840 (b) 8400 (c) 84
  22. 22.√76 to 1 decimal place? (a) 8.6 (b) 8.7 (c) 8.8 (d) 8.5
  23. 23.√61 to 1 decimal place? (a) 7.9 (b) 8.0 (c) 8.1 (d) 7.8
  24. 24.√98 to 1 decimal place? (a) 9.9 (b) 9.6 (c) 9.8 (d) 9.7
  25. 25.Best estimate of 2461 ÷ 86? (a) 2700 (b) 27 (c) 270
  26. 26.√63 to 1 decimal place? (a) 8.2 (b) 7.9 (c) 8.1 (d) 8.0
  27. 27.√26 to 1 decimal place? (a) 5.1 (b) 5.2 (c) 5.4 (d) 5.3
  28. 28.√83 to 1 decimal place? (a) 9.2 (b) 9.1 (c) 9.0 (d) 8.9
  29. 29.Best estimate of 1657 ÷ 38? (a) 410 (b) 41 (c) 4100
  30. 30.Best estimate of 2588 ÷ 29? (a) 8600 (b) 860 (c) 86
  31. 31.Best estimate of 3491 ÷ 42? (a) 870 (b) 8700 (c) 87
  32. 32.Best estimate of 770 ÷ 57? (a) 1300 (b) 13 (c) 130
  33. 33.Best estimate of 3452 ÷ 36? (a) 860 (b) 86 (c) 8600
  34. 34.√78 to 1 decimal place? (a) 8.8 (b) 8.9 (c) 8.7 (d) 9.0
  35. 35.Best estimate of 2304 ÷ 49? (a) 460 (b) 4600 (c) 46
  36. 36.Best estimate of 749 ÷ 57? (a) 12 (b) 120 (c) 1200
  37. 37.Best estimate of 3386 ÷ 88? (a) 3800 (b) 380 (c) 38
  38. 38.Best estimate of 4060 ÷ 73? (a) 5800 (b) 580 (c) 58
  39. 39.Best estimate of 4579 ÷ 83? (a) 57 (b) 5700 (c) 570
  40. 40.Best estimate of 2272 ÷ 39? (a) 57 (b) 5700 (c) 570

Answer key

  1. 86
  2. 5.8
  3. 32
  4. 8.6
  5. 84
  6. 65
  7. 32
  8. 9.4
  9. 27
  10. 18
  11. 6.6
  12. 84
  13. 6.2
  14. 89
  15. 41
  16. 4.8
  17. 9.3
  18. 6.1
  19. 7.1
  20. 66
  21. 84
  22. 8.7
  23. 7.8
  24. 9.9
  25. 27
  26. 7.9
  27. 5.1
  28. 9.1
  29. 41
  30. 86
  31. 87
  32. 13
  33. 86
  34. 8.8
  35. 46
  36. 12
  37. 38
  38. 58
  39. 57
  40. 57

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