← Estimate divisions and square roots lesson New set →

Estimating Square Roots and Division Worksheet

Mental maths lesson 27: Estimate divisions and square roots · Set 652 · 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 1877 ÷ 26? (a) 630 (b) 63 (c) 6300
  2. 2.√47 to 1 decimal place? (a) 6.9 (b) 6.6 (c) 6.7 (d) 6.8
  3. 3.Best estimate of 3885 ÷ 72? (a) 560 (b) 5600 (c) 56
  4. 4.√35 to 1 decimal place? (a) 6.0 (b) 6.2 (c) 5.9 (d) 6.1
  5. 5.Best estimate of 3907 ÷ 73? (a) 5600 (b) 56 (c) 560
  6. 6.√40 to 1 decimal place? (a) 6.1 (b) 6.2 (c) 6.3 (d) 6.4
  7. 7.Best estimate of 5077 ÷ 84? (a) 630 (b) 6300 (c) 63
  8. 8.√31 to 1 decimal place? (a) 5.5 (b) 5.4 (c) 5.6 (d) 5.3
  9. 9.√34 to 1 decimal place? (a) 5.5 (b) 5.7 (c) 5.8 (d) 5.6
  10. 10.Best estimate of 2117 ÷ 32? (a) 710 (b) 7100 (c) 71
  11. 11.Best estimate of 5839 ÷ 66? (a) 8300 (b) 83 (c) 830
  12. 12.Best estimate of 1800 ÷ 26? (a) 600 (b) 60 (c) 6000
  13. 13.√61 to 1 decimal place? (a) 7.7 (b) 7.8 (c) 7.9 (d) 8.0
  14. 14.Best estimate of 7360 ÷ 82? (a) 9200 (b) 92 (c) 920
  15. 15.Best estimate of 5855 ÷ 67? (a) 840 (b) 84 (c) 8400
  16. 16.Best estimate of 5027 ÷ 72? (a) 720 (b) 72 (c) 7200
  17. 17.Best estimate of 6258 ÷ 66? (a) 8900 (b) 890 (c) 89
  18. 18.Best estimate of 552 ÷ 32? (a) 18 (b) 180 (c) 1800
  19. 19.√84 to 1 decimal place? (a) 9.1 (b) 9.3 (c) 9.2 (d) 9.0
  20. 20.Best estimate of 4112 ÷ 47? (a) 820 (b) 8200 (c) 82
  21. 21.√82 to 1 decimal place? (a) 8.9 (b) 9.0 (c) 9.2 (d) 9.1
  22. 22.√28 to 1 decimal place? (a) 5.3 (b) 5.4 (c) 5.2 (d) 5.5
  23. 23.Best estimate of 2130 ÷ 61? (a) 3600 (b) 360 (c) 36
  24. 24.√87 to 1 decimal place? (a) 9.2 (b) 9.3 (c) 9.5 (d) 9.4
  25. 25.√41 to 1 decimal place? (a) 6.3 (b) 6.5 (c) 6.6 (d) 6.4
  26. 26.Best estimate of 3571 ÷ 76? (a) 450 (b) 4500 (c) 45
  27. 27.√37 to 1 decimal place? (a) 6.1 (b) 6.2 (c) 6.3 (d) 6.4
  28. 28.Best estimate of 4998 ÷ 66? (a) 71 (b) 710 (c) 7100
  29. 29.Best estimate of 4178 ÷ 56? (a) 70 (b) 7000 (c) 700
  30. 30.Best estimate of 3914 ÷ 71? (a) 56 (b) 560 (c) 5600
  31. 31.Best estimate of 4057 ÷ 68? (a) 580 (b) 58 (c) 5800
  32. 32.Best estimate of 1087 ÷ 39? (a) 270 (b) 2700 (c) 27
  33. 33.Best estimate of 1874 ÷ 28? (a) 6200 (b) 62 (c) 620
  34. 34.Best estimate of 1494 ÷ 59? (a) 250 (b) 25 (c) 2500
  35. 35.√44 to 1 decimal place? (a) 6.5 (b) 6.6 (c) 6.7 (d) 6.4
  36. 36.Best estimate of 1609 ÷ 32? (a) 5400 (b) 540 (c) 54
  37. 37.√92 to 1 decimal place? (a) 9.7 (b) 9.5 (c) 9.4 (d) 9.6
  38. 38.Best estimate of 1116 ÷ 48? (a) 220 (b) 2200 (c) 22
  39. 39.√55 to 1 decimal place? (a) 7.7 (b) 7.4 (c) 7.6 (d) 7.5
  40. 40.√58 to 1 decimal place? (a) 7.5 (b) 7.4 (c) 7.3 (d) 7.6

Answer key

  1. 63
  2. 6.9
  3. 56
  4. 5.9
  5. 56
  6. 6.3
  7. 63
  8. 5.6
  9. 5.8
  10. 71
  11. 83
  12. 60
  13. 7.8
  14. 92
  15. 84
  16. 72
  17. 89
  18. 18
  19. 9.2
  20. 82
  21. 9.1
  22. 5.3
  23. 36
  24. 9.3
  25. 6.4
  26. 45
  27. 6.1
  28. 71
  29. 70
  30. 56
  31. 58
  32. 27
  33. 62
  34. 25
  35. 6.6
  36. 54
  37. 9.6
  38. 22
  39. 7.4
  40. 7.6

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