← Estimate divisions and square roots lesson New set →

Estimating Square Roots and Division Worksheet

Mental maths lesson 27: Estimate divisions and square roots · Set 954 · 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.√92 to 1 decimal place? (a) 9.5 (b) 9.7 (c) 9.4 (d) 9.6
  2. 2.Best estimate of 5437 ÷ 71? (a) 780 (b) 7800 (c) 78
  3. 3.√59 to 1 decimal place? (a) 7.5 (b) 7.6 (c) 7.8 (d) 7.7
  4. 4.Best estimate of 909 ÷ 32? (a) 30 (b) 300 (c) 3000
  5. 5.Best estimate of 3334 ÷ 47? (a) 670 (b) 67 (c) 6700
  6. 6.√69 to 1 decimal place? (a) 8.3 (b) 8.0 (c) 8.2 (d) 8.1
  7. 7.Best estimate of 3004 ÷ 47? (a) 600 (b) 60 (c) 6000
  8. 8.Best estimate of 2194 ÷ 41? (a) 5500 (b) 550 (c) 55
  9. 9.√63 to 1 decimal place? (a) 7.9 (b) 7.7 (c) 7.8 (d) 7.6
  10. 10.√50 to 1 decimal place? (a) 6.9 (b) 7.1 (c) 7.0 (d) 7.2
  11. 11.√74 to 1 decimal place? (a) 8.5 (b) 8.7 (c) 8.6 (d) 8.8
  12. 12.√76 to 1 decimal place? (a) 8.5 (b) 8.7 (c) 8.6 (d) 8.8
  13. 13.√98 to 1 decimal place? (a) 10.2 (b) 10.1 (c) 10.0 (d) 9.9
  14. 14.Best estimate of 382 ÷ 26? (a) 1300 (b) 13 (c) 130
  15. 15.√40 to 1 decimal place? (a) 6.2 (b) 6.3 (c) 6.5 (d) 6.4
  16. 16.Best estimate of 3483 ÷ 72? (a) 500 (b) 5000 (c) 50
  17. 17.Best estimate of 4289 ÷ 62? (a) 7100 (b) 71 (c) 710
  18. 18.Best estimate of 1776 ÷ 36? (a) 4400 (b) 44 (c) 440
  19. 19.Best estimate of 1689 ÷ 36? (a) 42 (b) 420 (c) 4200
  20. 20.√88 to 1 decimal place? (a) 9.6 (b) 9.4 (c) 9.7 (d) 9.5
  21. 21.√51 to 1 decimal place? (a) 7.0 (b) 7.1 (c) 7.2 (d) 6.9
  22. 22.Best estimate of 2851 ÷ 86? (a) 32 (b) 3200 (c) 320
  23. 23.√78 to 1 decimal place? (a) 8.9 (b) 8.6 (c) 8.8 (d) 8.7
  24. 24.√82 to 1 decimal place? (a) 9.2 (b) 9.3 (c) 9.1 (d) 9.4
  25. 25.√32 to 1 decimal place? (a) 5.6 (b) 5.7 (c) 5.9 (d) 5.8
  26. 26.Best estimate of 1091 ÷ 41? (a) 2700 (b) 270 (c) 27
  27. 27.Best estimate of 2401 ÷ 42? (a) 6000 (b) 600 (c) 60
  28. 28.Best estimate of 3249 ÷ 42? (a) 81 (b) 810 (c) 8100
  29. 29.√94 to 1 decimal place? (a) 9.7 (b) 9.4 (c) 9.6 (d) 9.5
  30. 30.Best estimate of 3711 ÷ 44? (a) 930 (b) 93 (c) 9300
  31. 31.Best estimate of 6646 ÷ 79? (a) 8300 (b) 830 (c) 83
  32. 32.Best estimate of 3062 ÷ 72? (a) 44 (b) 440 (c) 4400
  33. 33.Best estimate of 2264 ÷ 34? (a) 750 (b) 7500 (c) 75
  34. 34.Best estimate of 7255 ÷ 82? (a) 910 (b) 91 (c) 9100
  35. 35.Best estimate of 1193 ÷ 43? (a) 3000 (b) 30 (c) 300
  36. 36.Best estimate of 3227 ÷ 34? (a) 10800 (b) 1080 (c) 108
  37. 37.Best estimate of 524 ÷ 22? (a) 2600 (b) 26 (c) 260
  38. 38.Best estimate of 871 ÷ 31? (a) 290 (b) 2900 (c) 29
  39. 39.√35 to 1 decimal place? (a) 6.2 (b) 5.9 (c) 6.1 (d) 6.0
  40. 40.√61 to 1 decimal place? (a) 7.9 (b) 8.1 (c) 8.0 (d) 7.8

Answer key

  1. 9.6
  2. 78
  3. 7.7
  4. 30
  5. 67
  6. 8.3
  7. 60
  8. 55
  9. 7.9
  10. 7.1
  11. 8.6
  12. 8.7
  13. 9.9
  14. 13
  15. 6.3
  16. 50
  17. 71
  18. 44
  19. 42
  20. 9.4
  21. 7.1
  22. 32
  23. 8.8
  24. 9.1
  25. 5.7
  26. 27
  27. 60
  28. 81
  29. 9.7
  30. 93
  31. 83
  32. 44
  33. 75
  34. 91
  35. 30
  36. 108
  37. 26
  38. 29
  39. 5.9
  40. 7.8

Free mental maths lessons, practice and worksheets at talentjr.in/mental-maths