← Estimate divisions and square roots lesson New set →

Estimating Square Roots and Division Worksheet

Mental maths lesson 27: Estimate divisions and square roots · Set 152 · 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 2467 ÷ 89? (a) 2700 (b) 27 (c) 270
  2. 2.√71 to 1 decimal place? (a) 8.4 (b) 8.3 (c) 8.2 (d) 8.1
  3. 3.√89 to 1 decimal place? (a) 9.5 (b) 9.3 (c) 9.6 (d) 9.4
  4. 4.Best estimate of 4449 ÷ 66? (a) 640 (b) 64 (c) 6400
  5. 5.Best estimate of 4185 ÷ 86? (a) 47 (b) 4700 (c) 470
  6. 6.√43 to 1 decimal place? (a) 6.6 (b) 6.4 (c) 6.7 (d) 6.5
  7. 7.Best estimate of 2731 ÷ 31? (a) 910 (b) 9100 (c) 91
  8. 8.√87 to 1 decimal place? (a) 9.4 (b) 9.6 (c) 9.3 (d) 9.5
  9. 9.Best estimate of 1691 ÷ 29? (a) 5600 (b) 560 (c) 56
  10. 10.√51 to 1 decimal place? (a) 7.1 (b) 7.0 (c) 6.9 (d) 7.2
  11. 11.Best estimate of 2752 ÷ 82? (a) 3400 (b) 340 (c) 34
  12. 12.√94 to 1 decimal place? (a) 9.6 (b) 9.7 (c) 9.8 (d) 9.5
  13. 13.Best estimate of 640 ÷ 31? (a) 2100 (b) 21 (c) 210
  14. 14.Best estimate of 786 ÷ 57? (a) 1300 (b) 130 (c) 13
  15. 15.√82 to 1 decimal place? (a) 9.0 (b) 9.2 (c) 8.9 (d) 9.1
  16. 16.Best estimate of 1371 ÷ 42? (a) 3400 (b) 34 (c) 340
  17. 17.√42 to 1 decimal place? (a) 6.4 (b) 6.5 (c) 6.3 (d) 6.6
  18. 18.√59 to 1 decimal place? (a) 7.5 (b) 7.4 (c) 7.7 (d) 7.6
  19. 19.√37 to 1 decimal place? (a) 6.3 (b) 6.1 (c) 6.2 (d) 6.0
  20. 20.Best estimate of 5736 ÷ 68? (a) 8200 (b) 82 (c) 820
  21. 21.√92 to 1 decimal place? (a) 9.8 (b) 9.5 (c) 9.6 (d) 9.7
  22. 22.√67 to 1 decimal place? (a) 8.4 (b) 8.3 (c) 8.1 (d) 8.2
  23. 23.Best estimate of 685 ÷ 26? (a) 230 (b) 2300 (c) 23
  24. 24.√40 to 1 decimal place? (a) 6.3 (b) 6.1 (c) 6.4 (d) 6.2
  25. 25.Best estimate of 1601 ÷ 26? (a) 530 (b) 5300 (c) 53
  26. 26.Best estimate of 3970 ÷ 66? (a) 570 (b) 5700 (c) 57
  27. 27.Best estimate of 5277 ÷ 61? (a) 8800 (b) 880 (c) 88
  28. 28.Best estimate of 2602 ÷ 53? (a) 52 (b) 520 (c) 5200
  29. 29.√50 to 1 decimal place? (a) 7.1 (b) 6.9 (c) 7.2 (d) 7.0
  30. 30.Best estimate of 2653 ÷ 52? (a) 530 (b) 53 (c) 5300
  31. 31.Best estimate of 713 ÷ 47? (a) 140 (b) 1400 (c) 14
  32. 32.Best estimate of 2651 ÷ 37? (a) 6600 (b) 66 (c) 660
  33. 33.Best estimate of 655 ÷ 54? (a) 1300 (b) 130 (c) 13
  34. 34.Best estimate of 2904 ÷ 33? (a) 97 (b) 970 (c) 9700
  35. 35.√76 to 1 decimal place? (a) 8.7 (b) 8.9 (c) 8.6 (d) 8.8
  36. 36.√41 to 1 decimal place? (a) 6.3 (b) 6.1 (c) 6.4 (d) 6.2
  37. 37.√83 to 1 decimal place? (a) 8.9 (b) 9.1 (c) 9.0 (d) 8.8
  38. 38.√69 to 1 decimal place? (a) 8.4 (b) 8.5 (c) 8.6 (d) 8.3
  39. 39.Best estimate of 3043 ÷ 41? (a) 7600 (b) 76 (c) 760
  40. 40.√62 to 1 decimal place? (a) 7.9 (b) 8.2 (c) 8.1 (d) 8.0

Answer key

  1. 27
  2. 8.4
  3. 9.4
  4. 64
  5. 47
  6. 6.6
  7. 91
  8. 9.3
  9. 56
  10. 7.1
  11. 34
  12. 9.7
  13. 21
  14. 13
  15. 9.1
  16. 34
  17. 6.5
  18. 7.7
  19. 6.1
  20. 82
  21. 9.6
  22. 8.2
  23. 23
  24. 6.3
  25. 53
  26. 57
  27. 88
  28. 52
  29. 7.1
  30. 53
  31. 14
  32. 66
  33. 13
  34. 97
  35. 8.7
  36. 6.4
  37. 9.1
  38. 8.3
  39. 76
  40. 7.9

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