← Estimate divisions and square roots lesson New set →

Estimating Square Roots and Division Worksheet

Mental maths lesson 27: Estimate divisions and square roots · Set 687 · 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.√82 to 1 decimal place? (a) 9.1 (b) 8.8 (c) 8.9 (d) 9.0
  2. 2.Best estimate of 8141 ÷ 87? (a) 9000 (b) 90 (c) 900
  3. 3.√40 to 1 decimal place? (a) 6.4 (b) 6.3 (c) 6.2 (d) 6.1
  4. 4.Best estimate of 698 ÷ 39? (a) 170 (b) 1700 (c) 17
  5. 5.√98 to 1 decimal place? (a) 9.9 (b) 9.7 (c) 9.6 (d) 9.8
  6. 6.√41 to 1 decimal place? (a) 6.3 (b) 6.2 (c) 6.1 (d) 6.4
  7. 7.Best estimate of 1996 ÷ 32? (a) 67 (b) 6700 (c) 670
  8. 8.Best estimate of 7812 ÷ 89? (a) 8700 (b) 870 (c) 87
  9. 9.√37 to 1 decimal place? (a) 6.3 (b) 6.0 (c) 6.2 (d) 6.1
  10. 10.Best estimate of 3441 ÷ 62? (a) 57 (b) 570 (c) 5700
  11. 11.√48 to 1 decimal place? (a) 6.9 (b) 7.0 (c) 6.8 (d) 6.7
  12. 12.Best estimate of 2034 ÷ 22? (a) 1020 (b) 102 (c) 10200
  13. 13.Best estimate of 2757 ÷ 73? (a) 39 (b) 390 (c) 3900
  14. 14.Best estimate of 6901 ÷ 84? (a) 8600 (b) 860 (c) 86
  15. 15.√43 to 1 decimal place? (a) 6.8 (b) 6.7 (c) 6.6 (d) 6.5
  16. 16.Best estimate of 1796 ÷ 29? (a) 60 (b) 6000 (c) 600
  17. 17.Best estimate of 2353 ÷ 36? (a) 59 (b) 590 (c) 5900
  18. 18.Best estimate of 5903 ÷ 82? (a) 740 (b) 74 (c) 7400
  19. 19.√52 to 1 decimal place? (a) 6.9 (b) 7.0 (c) 7.1 (d) 7.2
  20. 20.Best estimate of 2976 ÷ 32? (a) 9900 (b) 99 (c) 990
  21. 21.Best estimate of 1799 ÷ 33? (a) 6000 (b) 600 (c) 60
  22. 22.Best estimate of 3632 ÷ 44? (a) 910 (b) 9100 (c) 91
  23. 23.Best estimate of 2130 ÷ 71? (a) 3000 (b) 30 (c) 300
  24. 24.Best estimate of 3026 ÷ 88? (a) 340 (b) 34 (c) 3400
  25. 25.Best estimate of 4802 ÷ 77? (a) 6000 (b) 600 (c) 60
  26. 26.√21 to 1 decimal place? (a) 4.8 (b) 4.7 (c) 4.9 (d) 4.6
  27. 27.Best estimate of 1511 ÷ 86? (a) 17 (b) 170 (c) 1700
  28. 28.Best estimate of 826 ÷ 67? (a) 12 (b) 120 (c) 1200
  29. 29.√38 to 1 decimal place? (a) 6.4 (b) 6.2 (c) 6.3 (d) 6.5
  30. 30.√80 to 1 decimal place? (a) 8.7 (b) 8.8 (c) 9.0 (d) 8.9
  31. 31.√24 to 1 decimal place? (a) 5.2 (b) 5.1 (c) 4.9 (d) 5.0
  32. 32.Best estimate of 1667 ÷ 74? (a) 240 (b) 2400 (c) 24
  33. 33.Best estimate of 413 ÷ 34? (a) 140 (b) 1400 (c) 14
  34. 34.√90 to 1 decimal place? (a) 9.5 (b) 9.8 (c) 9.7 (d) 9.6
  35. 35.Best estimate of 4447 ÷ 56? (a) 74 (b) 740 (c) 7400
  36. 36.Best estimate of 2556 ÷ 38? (a) 6400 (b) 640 (c) 64
  37. 37.√87 to 1 decimal place? (a) 9.2 (b) 9.4 (c) 9.3 (d) 9.1
  38. 38.√71 to 1 decimal place? (a) 8.4 (b) 8.6 (c) 8.3 (d) 8.5
  39. 39.√53 to 1 decimal place? (a) 7.3 (b) 7.4 (c) 7.5 (d) 7.6
  40. 40.Best estimate of 1031 ÷ 42? (a) 260 (b) 26 (c) 2600

Answer key

  1. 9.1
  2. 90
  3. 6.3
  4. 17
  5. 9.9
  6. 6.4
  7. 67
  8. 87
  9. 6.1
  10. 57
  11. 6.9
  12. 102
  13. 39
  14. 86
  15. 6.6
  16. 60
  17. 59
  18. 74
  19. 7.2
  20. 99
  21. 60
  22. 91
  23. 30
  24. 34
  25. 60
  26. 4.6
  27. 17
  28. 12
  29. 6.2
  30. 8.9
  31. 4.9
  32. 24
  33. 14
  34. 9.5
  35. 74
  36. 64
  37. 9.3
  38. 8.4
  39. 7.3
  40. 26

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