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Estimating Square Roots and Division Worksheet

Mental maths lesson 27: Estimate divisions and square roots · Set 653 · 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.√58 to 1 decimal place? (a) 7.3 (b) 7.6 (c) 7.4 (d) 7.5
  2. 2.√98 to 1 decimal place? (a) 10.0 (b) 9.7 (c) 9.9 (d) 9.8
  3. 3.Best estimate of 1328 ÷ 46? (a) 270 (b) 2700 (c) 27
  4. 4.Best estimate of 1361 ÷ 23? (a) 680 (b) 6800 (c) 68
  5. 5.Best estimate of 1758 ÷ 82? (a) 2200 (b) 22 (c) 220
  6. 6.Best estimate of 3951 ÷ 54? (a) 7900 (b) 79 (c) 790
  7. 7.√88 to 1 decimal place? (a) 9.5 (b) 9.4 (c) 9.6 (d) 9.3
  8. 8.√72 to 1 decimal place? (a) 8.4 (b) 8.5 (c) 8.6 (d) 8.3
  9. 9.√31 to 1 decimal place? (a) 5.7 (b) 5.8 (c) 5.6 (d) 5.5
  10. 10.Best estimate of 4752 ÷ 84? (a) 5900 (b) 59 (c) 590
  11. 11.√50 to 1 decimal place? (a) 7.4 (b) 7.1 (c) 7.3 (d) 7.2
  12. 12.Best estimate of 6882 ÷ 74? (a) 9800 (b) 980 (c) 98
  13. 13.Best estimate of 3170 ÷ 53? (a) 630 (b) 6300 (c) 63
  14. 14.√37 to 1 decimal place? (a) 6.2 (b) 6.3 (c) 6.1 (d) 6.4
  15. 15.√35 to 1 decimal place? (a) 5.7 (b) 5.8 (c) 5.9 (d) 5.6
  16. 16.√74 to 1 decimal place? (a) 8.6 (b) 8.9 (c) 8.7 (d) 8.8
  17. 17.√51 to 1 decimal place? (a) 7.2 (b) 7.1 (c) 7.0 (d) 6.9
  18. 18.Best estimate of 5504 ÷ 58? (a) 920 (b) 9200 (c) 92
  19. 19.Best estimate of 5680 ÷ 74? (a) 810 (b) 8100 (c) 81
  20. 20.√55 to 1 decimal place? (a) 7.5 (b) 7.4 (c) 7.3 (d) 7.2
  21. 21.√42 to 1 decimal place? (a) 6.7 (b) 6.4 (c) 6.6 (d) 6.5
  22. 22.Best estimate of 2082 ÷ 59? (a) 3500 (b) 350 (c) 35
  23. 23.√69 to 1 decimal place? (a) 8.4 (b) 8.2 (c) 8.5 (d) 8.3
  24. 24.√61 to 1 decimal place? (a) 7.5 (b) 7.6 (c) 7.7 (d) 7.8
  25. 25.Best estimate of 5566 ÷ 77? (a) 700 (b) 70 (c) 7000
  26. 26.Best estimate of 2178 ÷ 37? (a) 54 (b) 540 (c) 5400
  27. 27.√22 to 1 decimal place? (a) 4.7 (b) 4.6 (c) 4.5 (d) 4.8
  28. 28.√30 to 1 decimal place? (a) 5.5 (b) 5.4 (c) 5.6 (d) 5.7
  29. 29.Best estimate of 2745 ÷ 86? (a) 31 (b) 3100 (c) 310
  30. 30.Best estimate of 3655 ÷ 69? (a) 520 (b) 5200 (c) 52
  31. 31.Best estimate of 2830 ÷ 42? (a) 7100 (b) 71 (c) 710
  32. 32.Best estimate of 2282 ÷ 43? (a) 5700 (b) 570 (c) 57
  33. 33.Best estimate of 5800 ÷ 89? (a) 640 (b) 6400 (c) 64
  34. 34.Best estimate of 3222 ÷ 58? (a) 5400 (b) 540 (c) 54
  35. 35.Best estimate of 3478 ÷ 48? (a) 70 (b) 700 (c) 7000
  36. 36.Best estimate of 3294 ÷ 61? (a) 550 (b) 5500 (c) 55
  37. 37.Best estimate of 2202 ÷ 54? (a) 4400 (b) 440 (c) 44
  38. 38.Best estimate of 852 ÷ 46? (a) 17 (b) 1700 (c) 170
  39. 39.Best estimate of 5330 ÷ 62? (a) 890 (b) 8900 (c) 89
  40. 40.√34 to 1 decimal place? (a) 5.7 (b) 5.8 (c) 5.9 (d) 5.6

Answer key

  1. 7.6
  2. 9.9
  3. 27
  4. 68
  5. 22
  6. 79
  7. 9.4
  8. 8.5
  9. 5.6
  10. 59
  11. 7.1
  12. 98
  13. 63
  14. 6.1
  15. 5.9
  16. 8.6
  17. 7.1
  18. 92
  19. 81
  20. 7.4
  21. 6.5
  22. 35
  23. 8.3
  24. 7.8
  25. 70
  26. 54
  27. 4.7
  28. 5.5
  29. 31
  30. 52
  31. 71
  32. 57
  33. 64
  34. 54
  35. 70
  36. 55
  37. 44
  38. 17
  39. 89
  40. 5.8

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