← Estimate divisions and square roots lesson New set →

Estimating Square Roots and Division Worksheet

Mental maths lesson 27: Estimate divisions and square roots · Set 655 · 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) 5.8 (b) 5.9 (c) 6.1 (d) 6.0
  2. 2.Best estimate of 884 ÷ 22? (a) 440 (b) 44 (c) 4400
  3. 3.Best estimate of 2176 ÷ 76? (a) 270 (b) 2700 (c) 27
  4. 4.Best estimate of 1168 ÷ 43? (a) 290 (b) 29 (c) 2900
  5. 5.√55 to 1 decimal place? (a) 7.3 (b) 7.2 (c) 7.5 (d) 7.4
  6. 6.√77 to 1 decimal place? (a) 9.0 (b) 9.1 (c) 8.9 (d) 8.8
  7. 7.√24 to 1 decimal place? (a) 5.1 (b) 4.8 (c) 5.0 (d) 4.9
  8. 8.√98 to 1 decimal place? (a) 10.2 (b) 10.1 (c) 9.9 (d) 10.0
  9. 9.Best estimate of 3972 ÷ 61? (a) 66 (b) 6600 (c) 660
  10. 10.Best estimate of 4696 ÷ 78? (a) 5900 (b) 59 (c) 590
  11. 11.Best estimate of 4110 ÷ 53? (a) 8200 (b) 820 (c) 82
  12. 12.Best estimate of 2518 ÷ 42? (a) 63 (b) 6300 (c) 630
  13. 13.√29 to 1 decimal place? (a) 5.6 (b) 5.4 (c) 5.7 (d) 5.5
  14. 14.Best estimate of 2292 ÷ 71? (a) 3300 (b) 330 (c) 33
  15. 15.Best estimate of 1699 ÷ 29? (a) 5700 (b) 57 (c) 570
  16. 16.Best estimate of 2005 ÷ 22? (a) 100 (b) 1000 (c) 10000
  17. 17.Best estimate of 2636 ÷ 51? (a) 530 (b) 5300 (c) 53
  18. 18.√58 to 1 decimal place? (a) 7.6 (b) 7.7 (c) 7.8 (d) 7.5
  19. 19.√90 to 1 decimal place? (a) 9.7 (b) 9.8 (c) 9.5 (d) 9.6
  20. 20.Best estimate of 2852 ÷ 78? (a) 36 (b) 360 (c) 3600
  21. 21.√94 to 1 decimal place? (a) 9.6 (b) 9.7 (c) 9.5 (d) 9.8
  22. 22.Best estimate of 1163 ÷ 79? (a) 1500 (b) 15 (c) 150
  23. 23.Best estimate of 593 ÷ 33? (a) 2000 (b) 20 (c) 200
  24. 24.Best estimate of 597 ÷ 41? (a) 15 (b) 150 (c) 1500
  25. 25.√86 to 1 decimal place? (a) 9.3 (b) 9.4 (c) 9.1 (d) 9.2
  26. 26.Best estimate of 4136 ÷ 86? (a) 4600 (b) 46 (c) 460
  27. 27.√28 to 1 decimal place? (a) 5.2 (b) 5.1 (c) 5.3 (d) 5.0
  28. 28.Best estimate of 791 ÷ 27? (a) 260 (b) 2600 (c) 26
  29. 29.√96 to 1 decimal place? (a) 9.9 (b) 9.8 (c) 10.1 (d) 10.0
  30. 30.√20 to 1 decimal place? (a) 4.5 (b) 4.4 (c) 4.3 (d) 4.2
  31. 31.Best estimate of 4777 ÷ 57? (a) 8000 (b) 80 (c) 800
  32. 32.Best estimate of 1459 ÷ 22? (a) 7300 (b) 730 (c) 73
  33. 33.√87 to 1 decimal place? (a) 9.5 (b) 9.2 (c) 9.4 (d) 9.3
  34. 34.√47 to 1 decimal place? (a) 7.1 (b) 7.0 (c) 6.9 (d) 6.8
  35. 35.Best estimate of 833 ÷ 41? (a) 2100 (b) 21 (c) 210
  36. 36.Best estimate of 6695 ÷ 78? (a) 840 (b) 84 (c) 8400
  37. 37.Best estimate of 2247 ÷ 29? (a) 750 (b) 75 (c) 7500
  38. 38.Best estimate of 849 ÷ 31? (a) 2800 (b) 28 (c) 280
  39. 39.Best estimate of 2510 ÷ 78? (a) 310 (b) 3100 (c) 31
  40. 40.Best estimate of 4279 ÷ 46? (a) 86 (b) 8600 (c) 860

Answer key

  1. 6.1
  2. 44
  3. 27
  4. 29
  5. 7.4
  6. 8.8
  7. 4.9
  8. 9.9
  9. 66
  10. 59
  11. 82
  12. 63
  13. 5.4
  14. 33
  15. 57
  16. 100
  17. 53
  18. 7.6
  19. 9.5
  20. 36
  21. 9.7
  22. 15
  23. 20
  24. 15
  25. 9.3
  26. 46
  27. 5.3
  28. 26
  29. 9.8
  30. 4.5
  31. 80
  32. 73
  33. 9.3
  34. 6.9
  35. 21
  36. 84
  37. 75
  38. 28
  39. 31
  40. 86

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