← Estimate divisions and square roots lesson New set →

Estimating Square Roots and Division Worksheet

Mental maths lesson 27: Estimate divisions and square roots · Set 41 · 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.√37 to 1 decimal place? (a) 6.2 (b) 6.0 (c) 5.9 (d) 6.1
  2. 2.Best estimate of 1165 ÷ 42? (a) 2900 (b) 290 (c) 29
  3. 3.√20 to 1 decimal place? (a) 4.6 (b) 4.8 (c) 4.5 (d) 4.7
  4. 4.Best estimate of 847 ÷ 51? (a) 170 (b) 17 (c) 1700
  5. 5.√76 to 1 decimal place? (a) 8.5 (b) 8.4 (c) 8.6 (d) 8.7
  6. 6.√26 to 1 decimal place? (a) 5.0 (b) 4.8 (c) 4.9 (d) 5.1
  7. 7.√66 to 1 decimal place? (a) 8.2 (b) 8.1 (c) 8.4 (d) 8.3
  8. 8.√96 to 1 decimal place? (a) 10.0 (b) 10.1 (c) 9.8 (d) 9.9
  9. 9.Best estimate of 1127 ÷ 34? (a) 380 (b) 3800 (c) 38
  10. 10.Best estimate of 6051 ÷ 82? (a) 7600 (b) 760 (c) 76
  11. 11.Best estimate of 4232 ÷ 68? (a) 6000 (b) 600 (c) 60
  12. 12.Best estimate of 1083 ÷ 31? (a) 360 (b) 3600 (c) 36
  13. 13.√92 to 1 decimal place? (a) 9.4 (b) 9.6 (c) 9.5 (d) 9.3
  14. 14.√53 to 1 decimal place? (a) 7.3 (b) 7.5 (c) 7.2 (d) 7.4
  15. 15.√51 to 1 decimal place? (a) 7.0 (b) 7.2 (c) 7.1 (d) 6.9
  16. 16.Best estimate of 539 ÷ 22? (a) 27 (b) 2700 (c) 270
  17. 17.Best estimate of 3693 ÷ 86? (a) 4100 (b) 410 (c) 41
  18. 18.Best estimate of 2334 ÷ 54? (a) 47 (b) 470 (c) 4700
  19. 19.Best estimate of 5171 ÷ 76? (a) 650 (b) 65 (c) 6500
  20. 20.√58 to 1 decimal place? (a) 7.6 (b) 7.8 (c) 7.7 (d) 7.5
  21. 21.Best estimate of 1522 ÷ 84? (a) 190 (b) 1900 (c) 19
  22. 22.Best estimate of 4195 ÷ 73? (a) 6000 (b) 60 (c) 600
  23. 23.√52 to 1 decimal place? (a) 7.2 (b) 7.1 (c) 6.9 (d) 7.0
  24. 24.Best estimate of 4766 ÷ 62? (a) 79 (b) 790 (c) 7900
  25. 25.Best estimate of 2985 ÷ 48? (a) 6000 (b) 600 (c) 60
  26. 26.Best estimate of 5009 ÷ 56? (a) 83 (b) 8300 (c) 830
  27. 27.Best estimate of 3938 ÷ 54? (a) 79 (b) 7900 (c) 790
  28. 28.√44 to 1 decimal place? (a) 6.7 (b) 6.9 (c) 6.8 (d) 6.6
  29. 29.√35 to 1 decimal place? (a) 5.6 (b) 5.9 (c) 5.8 (d) 5.7
  30. 30.√74 to 1 decimal place? (a) 8.7 (b) 8.6 (c) 8.8 (d) 8.9
  31. 31.√87 to 1 decimal place? (a) 9.3 (b) 9.2 (c) 9.5 (d) 9.4
  32. 32.Best estimate of 1391 ÷ 29? (a) 4600 (b) 460 (c) 46
  33. 33.Best estimate of 732 ÷ 34? (a) 24 (b) 240 (c) 2400
  34. 34.Best estimate of 1245 ÷ 36? (a) 310 (b) 31 (c) 3100
  35. 35.√43 to 1 decimal place? (a) 6.5 (b) 6.6 (c) 6.3 (d) 6.4
  36. 36.√34 to 1 decimal place? (a) 6.0 (b) 5.9 (c) 5.7 (d) 5.8
  37. 37.Best estimate of 7594 ÷ 81? (a) 950 (b) 95 (c) 9500
  38. 38.Best estimate of 2443 ÷ 66? (a) 3500 (b) 350 (c) 35
  39. 39.√38 to 1 decimal place? (a) 6.3 (b) 6.5 (c) 6.2 (d) 6.4
  40. 40.√21 to 1 decimal place? (a) 4.8 (b) 4.6 (c) 4.7 (d) 4.5

Answer key

  1. 6.1
  2. 29
  3. 4.5
  4. 17
  5. 8.7
  6. 5.1
  7. 8.1
  8. 9.8
  9. 38
  10. 76
  11. 60
  12. 36
  13. 9.6
  14. 7.3
  15. 7.1
  16. 27
  17. 41
  18. 47
  19. 65
  20. 7.6
  21. 19
  22. 60
  23. 7.2
  24. 79
  25. 60
  26. 83
  27. 79
  28. 6.6
  29. 5.9
  30. 8.6
  31. 9.3
  32. 46
  33. 24
  34. 31
  35. 6.6
  36. 5.8
  37. 95
  38. 35
  39. 6.2
  40. 4.6

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