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Estimating Square Roots and Division Worksheet

Mental maths lesson 27: Estimate divisions and square roots · Set 241 · 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 2243 ÷ 27? (a) 750 (b) 75 (c) 7500
  2. 2.√50 to 1 decimal place? (a) 7.3 (b) 7.4 (c) 7.1 (d) 7.2
  3. 3.√65 to 1 decimal place? (a) 8.1 (b) 8.2 (c) 8.0 (d) 8.3
  4. 4.Best estimate of 1779 ÷ 82? (a) 22 (b) 2200 (c) 220
  5. 5.√24 to 1 decimal place? (a) 4.9 (b) 5.0 (c) 5.1 (d) 4.8
  6. 6.√66 to 1 decimal place? (a) 8.2 (b) 8.1 (c) 8.0 (d) 8.3
  7. 7.Best estimate of 8171 ÷ 88? (a) 91 (b) 9100 (c) 910
  8. 8.Best estimate of 5488 ÷ 77? (a) 690 (b) 6900 (c) 69
  9. 9.Best estimate of 2227 ÷ 63? (a) 37 (b) 370 (c) 3700
  10. 10.Best estimate of 3563 ÷ 52? (a) 710 (b) 7100 (c) 71
  11. 11.Best estimate of 4986 ÷ 53? (a) 10000 (b) 100 (c) 1000
  12. 12.Best estimate of 5611 ÷ 76? (a) 70 (b) 7000 (c) 700
  13. 13.√29 to 1 decimal place? (a) 5.7 (b) 5.4 (c) 5.6 (d) 5.5
  14. 14.Best estimate of 4212 ÷ 46? (a) 8400 (b) 840 (c) 84
  15. 15.Best estimate of 5024 ÷ 53? (a) 1000 (b) 100 (c) 10000
  16. 16.√43 to 1 decimal place? (a) 6.7 (b) 6.6 (c) 6.8 (d) 6.5
  17. 17.Best estimate of 1575 ÷ 27? (a) 5300 (b) 53 (c) 530
  18. 18.√98 to 1 decimal place? (a) 9.8 (b) 9.6 (c) 9.7 (d) 9.9
  19. 19.√38 to 1 decimal place? (a) 6.5 (b) 6.2 (c) 6.4 (d) 6.3
  20. 20.Best estimate of 2458 ÷ 62? (a) 4100 (b) 41 (c) 410
  21. 21.√61 to 1 decimal place? (a) 7.7 (b) 7.5 (c) 7.6 (d) 7.8
  22. 22.Best estimate of 3587 ÷ 68? (a) 51 (b) 5100 (c) 510
  23. 23.Best estimate of 489 ÷ 34? (a) 16 (b) 160 (c) 1600
  24. 24.Best estimate of 1080 ÷ 54? (a) 2200 (b) 220 (c) 22
  25. 25.√53 to 1 decimal place? (a) 7.3 (b) 7.2 (c) 7.4 (d) 7.1
  26. 26.√74 to 1 decimal place? (a) 8.7 (b) 8.9 (c) 8.6 (d) 8.8
  27. 27.Best estimate of 1367 ÷ 36? (a) 3400 (b) 340 (c) 34
  28. 28.√82 to 1 decimal place? (a) 9.1 (b) 9.0 (c) 9.2 (d) 8.9
  29. 29.Best estimate of 1876 ÷ 24? (a) 94 (b) 940 (c) 9400
  30. 30.Best estimate of 3467 ÷ 61? (a) 5800 (b) 580 (c) 58
  31. 31.Best estimate of 1622 ÷ 26? (a) 54 (b) 540 (c) 5400
  32. 32.Best estimate of 4576 ÷ 71? (a) 650 (b) 65 (c) 6500
  33. 33.√59 to 1 decimal place? (a) 7.6 (b) 7.7 (c) 7.5 (d) 7.4
  34. 34.Best estimate of 1828 ÷ 24? (a) 910 (b) 9100 (c) 91
  35. 35.√92 to 1 decimal place? (a) 9.4 (b) 9.6 (c) 9.5 (d) 9.3
  36. 36.Best estimate of 733 ÷ 26? (a) 24 (b) 2400 (c) 240
  37. 37.Best estimate of 2877 ÷ 82? (a) 36 (b) 3600 (c) 360
  38. 38.Best estimate of 1480 ÷ 28? (a) 49 (b) 4900 (c) 490
  39. 39.Best estimate of 5560 ÷ 62? (a) 930 (b) 93 (c) 9300
  40. 40.Best estimate of 684 ÷ 24? (a) 34 (b) 340 (c) 3400

Answer key

  1. 75
  2. 7.1
  3. 8.1
  4. 22
  5. 4.9
  6. 8.1
  7. 91
  8. 69
  9. 37
  10. 71
  11. 100
  12. 70
  13. 5.4
  14. 84
  15. 100
  16. 6.6
  17. 53
  18. 9.9
  19. 6.2
  20. 41
  21. 7.8
  22. 51
  23. 16
  24. 22
  25. 7.3
  26. 8.6
  27. 34
  28. 9.1
  29. 94
  30. 58
  31. 54
  32. 65
  33. 7.7
  34. 91
  35. 9.6
  36. 24
  37. 36
  38. 49
  39. 93
  40. 34

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