← Estimate divisions and square roots lesson New set →

Estimating Square Roots and Division Worksheet

Mental maths lesson 27: Estimate divisions and square roots · Set 87 · 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.√94 to 1 decimal place? (a) 9.5 (b) 9.6 (c) 9.4 (d) 9.7
  2. 2.Best estimate of 832 ÷ 59? (a) 14 (b) 1400 (c) 140
  3. 3.Best estimate of 5008 ÷ 57? (a) 83 (b) 830 (c) 8300
  4. 4.Best estimate of 1966 ÷ 58? (a) 330 (b) 33 (c) 3300
  5. 5.Best estimate of 3020 ÷ 46? (a) 60 (b) 6000 (c) 600
  6. 6.Best estimate of 2367 ÷ 61? (a) 39 (b) 3900 (c) 390
  7. 7.Best estimate of 3316 ÷ 54? (a) 66 (b) 660 (c) 6600
  8. 8.Best estimate of 1185 ÷ 33? (a) 400 (b) 40 (c) 4000
  9. 9.√82 to 1 decimal place? (a) 9.4 (b) 9.3 (c) 9.1 (d) 9.2
  10. 10.Best estimate of 2547 ÷ 42? (a) 640 (b) 6400 (c) 64
  11. 11.√24 to 1 decimal place? (a) 5.0 (b) 4.9 (c) 5.2 (d) 5.1
  12. 12.Best estimate of 939 ÷ 32? (a) 310 (b) 3100 (c) 31
  13. 13.Best estimate of 4471 ÷ 68? (a) 6400 (b) 640 (c) 64
  14. 14.√67 to 1 decimal place? (a) 8.1 (b) 8.4 (c) 8.3 (d) 8.2
  15. 15.Best estimate of 773 ÷ 42? (a) 1900 (b) 190 (c) 19
  16. 16.Best estimate of 4953 ÷ 53? (a) 9900 (b) 99 (c) 990
  17. 17.Best estimate of 642 ÷ 53? (a) 130 (b) 1300 (c) 13
  18. 18.Best estimate of 5156 ÷ 87? (a) 57 (b) 570 (c) 5700
  19. 19.√40 to 1 decimal place? (a) 6.2 (b) 6.3 (c) 6.5 (d) 6.4
  20. 20.√90 to 1 decimal place? (a) 9.7 (b) 9.8 (c) 9.6 (d) 9.5
  21. 21.√22 to 1 decimal place? (a) 4.8 (b) 5.0 (c) 4.7 (d) 4.9
  22. 22.Best estimate of 2177 ÷ 29? (a) 730 (b) 73 (c) 7300
  23. 23.Best estimate of 2251 ÷ 28? (a) 75 (b) 7500 (c) 750
  24. 24.√20 to 1 decimal place? (a) 4.6 (b) 4.5 (c) 4.8 (d) 4.7
  25. 25.Best estimate of 1006 ÷ 66? (a) 140 (b) 1400 (c) 14
  26. 26.√92 to 1 decimal place? (a) 9.6 (b) 9.8 (c) 9.5 (d) 9.7
  27. 27.√26 to 1 decimal place? (a) 5.3 (b) 5.1 (c) 5.4 (d) 5.2
  28. 28.Best estimate of 4148 ÷ 49? (a) 830 (b) 83 (c) 8300
  29. 29.Best estimate of 3974 ÷ 63? (a) 66 (b) 660 (c) 6600
  30. 30.√65 to 1 decimal place? (a) 8.3 (b) 8.4 (c) 8.2 (d) 8.1
  31. 31.Best estimate of 4968 ÷ 58? (a) 83 (b) 8300 (c) 830
  32. 32.√53 to 1 decimal place? (a) 7.4 (b) 7.2 (c) 7.1 (d) 7.3
  33. 33.Best estimate of 804 ÷ 54? (a) 160 (b) 1600 (c) 16
  34. 34.Best estimate of 4768 ÷ 71? (a) 68 (b) 680 (c) 6800
  35. 35.Best estimate of 2422 ÷ 31? (a) 810 (b) 81 (c) 8100
  36. 36.Best estimate of 3430 ÷ 51? (a) 690 (b) 6900 (c) 69
  37. 37.Best estimate of 2248 ÷ 51? (a) 4500 (b) 45 (c) 450
  38. 38.Best estimate of 2611 ÷ 68? (a) 370 (b) 37 (c) 3700
  39. 39.√38 to 1 decimal place? (a) 6.1 (b) 6.0 (c) 6.2 (d) 6.3
  40. 40.Best estimate of 1469 ÷ 23? (a) 7300 (b) 730 (c) 73

Answer key

  1. 9.7
  2. 14
  3. 83
  4. 33
  5. 60
  6. 39
  7. 66
  8. 40
  9. 9.1
  10. 64
  11. 4.9
  12. 31
  13. 64
  14. 8.2
  15. 19
  16. 99
  17. 13
  18. 57
  19. 6.3
  20. 9.5
  21. 4.7
  22. 73
  23. 75
  24. 4.5
  25. 14
  26. 9.6
  27. 5.1
  28. 83
  29. 66
  30. 8.1
  31. 83
  32. 7.3
  33. 16
  34. 68
  35. 81
  36. 69
  37. 45
  38. 37
  39. 6.2
  40. 73

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