← Estimate divisions and square roots lesson New set →

Estimating Square Roots and Division Worksheet

Mental maths lesson 27: Estimate divisions and square roots · Set 75 · 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 4080 ÷ 71? (a) 58 (b) 5800 (c) 580
  2. 2.√82 to 1 decimal place? (a) 8.8 (b) 9.1 (c) 9.0 (d) 8.9
  3. 3.√22 to 1 decimal place? (a) 4.5 (b) 4.7 (c) 4.6 (d) 4.4
  4. 4.√86 to 1 decimal place? (a) 9.1 (b) 9.3 (c) 9.4 (d) 9.2
  5. 5.Best estimate of 1896 ÷ 87? (a) 210 (b) 21 (c) 2100
  6. 6.Best estimate of 3343 ÷ 71? (a) 48 (b) 480 (c) 4800
  7. 7.√27 to 1 decimal place? (a) 5.4 (b) 5.1 (c) 5.2 (d) 5.3
  8. 8.Best estimate of 4729 ÷ 61? (a) 79 (b) 7900 (c) 790
  9. 9.√77 to 1 decimal place? (a) 8.9 (b) 8.6 (c) 8.8 (d) 8.7
  10. 10.Best estimate of 985 ÷ 34? (a) 3300 (b) 330 (c) 33
  11. 11.Best estimate of 1403 ÷ 29? (a) 470 (b) 4700 (c) 47
  12. 12.√72 to 1 decimal place? (a) 8.4 (b) 8.6 (c) 8.5 (d) 8.7
  13. 13.Best estimate of 3732 ÷ 42? (a) 930 (b) 9300 (c) 93
  14. 14.Best estimate of 1896 ÷ 73? (a) 270 (b) 27 (c) 2700
  15. 15.√44 to 1 decimal place? (a) 6.3 (b) 6.6 (c) 6.4 (d) 6.5
  16. 16.Best estimate of 611 ÷ 41? (a) 15 (b) 1500 (c) 150
  17. 17.Best estimate of 1413 ÷ 23? (a) 71 (b) 7100 (c) 710
  18. 18.Best estimate of 4231 ÷ 59? (a) 710 (b) 7100 (c) 71
  19. 19.Best estimate of 5928 ÷ 68? (a) 850 (b) 8500 (c) 85
  20. 20.Best estimate of 3363 ÷ 52? (a) 670 (b) 67 (c) 6700
  21. 21.Best estimate of 1587 ÷ 37? (a) 4000 (b) 40 (c) 400
  22. 22.Best estimate of 2064 ÷ 89? (a) 2300 (b) 23 (c) 230
  23. 23.Best estimate of 4172 ÷ 86? (a) 4600 (b) 460 (c) 46
  24. 24.Best estimate of 3482 ÷ 78? (a) 4400 (b) 44 (c) 440
  25. 25.√26 to 1 decimal place? (a) 5.0 (b) 5.1 (c) 5.2 (d) 4.9
  26. 26.Best estimate of 1789 ÷ 49? (a) 360 (b) 3600 (c) 36
  27. 27.Best estimate of 4268 ÷ 84? (a) 5300 (b) 530 (c) 53
  28. 28.Best estimate of 2915 ÷ 38? (a) 730 (b) 73 (c) 7300
  29. 29.Best estimate of 2435 ÷ 31? (a) 8100 (b) 810 (c) 81
  30. 30.√71 to 1 decimal place? (a) 8.3 (b) 8.5 (c) 8.2 (d) 8.4
  31. 31.Best estimate of 3765 ÷ 73? (a) 540 (b) 5400 (c) 54
  32. 32.Best estimate of 6278 ÷ 73? (a) 900 (b) 9000 (c) 90
  33. 33.Best estimate of 5607 ÷ 63? (a) 9300 (b) 930 (c) 93
  34. 34.Best estimate of 4636 ÷ 72? (a) 6600 (b) 660 (c) 66
  35. 35.√66 to 1 decimal place? (a) 7.9 (b) 8.0 (c) 8.1 (d) 7.8
  36. 36.√51 to 1 decimal place? (a) 7.4 (b) 7.3 (c) 7.1 (d) 7.2
  37. 37.Best estimate of 2231 ÷ 89? (a) 250 (b) 2500 (c) 25
  38. 38.Best estimate of 1740 ÷ 88? (a) 1900 (b) 19 (c) 190
  39. 39.√52 to 1 decimal place? (a) 7.2 (b) 7.0 (c) 7.1 (d) 7.3
  40. 40.Best estimate of 7290 ÷ 82? (a) 910 (b) 91 (c) 9100

Answer key

  1. 58
  2. 9.1
  3. 4.7
  4. 9.3
  5. 21
  6. 48
  7. 5.2
  8. 79
  9. 8.8
  10. 33
  11. 47
  12. 8.5
  13. 93
  14. 27
  15. 6.6
  16. 15
  17. 71
  18. 71
  19. 85
  20. 67
  21. 40
  22. 23
  23. 46
  24. 44
  25. 5.1
  26. 36
  27. 53
  28. 73
  29. 81
  30. 8.4
  31. 54
  32. 90
  33. 93
  34. 66
  35. 8.1
  36. 7.1
  37. 25
  38. 19
  39. 7.2
  40. 91

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