← Estimate divisions and square roots lesson New set →

Estimating Square Roots and Division Worksheet

Mental maths lesson 27: Estimate divisions and square roots · Set 773 · 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.√47 to 1 decimal place? (a) 7.0 (b) 6.9 (c) 7.1 (d) 6.8
  2. 2.√34 to 1 decimal place? (a) 5.8 (b) 5.7 (c) 5.9 (d) 5.6
  3. 3.Best estimate of 5730 ÷ 69? (a) 820 (b) 8200 (c) 82
  4. 4.Best estimate of 1756 ÷ 49? (a) 3500 (b) 350 (c) 35
  5. 5.Best estimate of 4194 ÷ 44? (a) 1050 (b) 105 (c) 10500
  6. 6.Best estimate of 2693 ÷ 44? (a) 67 (b) 6700 (c) 670
  7. 7.Best estimate of 4317 ÷ 72? (a) 6200 (b) 620 (c) 62
  8. 8.√85 to 1 decimal place? (a) 9.1 (b) 9.0 (c) 8.9 (d) 9.2
  9. 9.√96 to 1 decimal place? (a) 9.8 (b) 9.5 (c) 9.7 (d) 9.6
  10. 10.√90 to 1 decimal place? (a) 9.7 (b) 9.6 (c) 9.8 (d) 9.5
  11. 11.Best estimate of 2274 ÷ 36? (a) 5700 (b) 57 (c) 570
  12. 12.Best estimate of 5354 ÷ 76? (a) 67 (b) 6700 (c) 670
  13. 13.√79 to 1 decimal place? (a) 8.7 (b) 8.8 (c) 9.0 (d) 8.9
  14. 14.Best estimate of 5713 ÷ 78? (a) 71 (b) 7100 (c) 710
  15. 15.√28 to 1 decimal place? (a) 5.2 (b) 5.3 (c) 5.1 (d) 5.0
  16. 16.√71 to 1 decimal place? (a) 8.5 (b) 8.6 (c) 8.7 (d) 8.4
  17. 17.√23 to 1 decimal place? (a) 4.7 (b) 4.5 (c) 4.8 (d) 4.6
  18. 18.√32 to 1 decimal place? (a) 5.6 (b) 5.9 (c) 5.7 (d) 5.8
  19. 19.Best estimate of 5282 ÷ 61? (a) 8800 (b) 88 (c) 880
  20. 20.Best estimate of 5934 ÷ 78? (a) 7400 (b) 74 (c) 740
  21. 21.Best estimate of 3387 ÷ 82? (a) 4200 (b) 42 (c) 420
  22. 22.Best estimate of 1022 ÷ 32? (a) 340 (b) 3400 (c) 34
  23. 23.Best estimate of 2858 ÷ 62? (a) 4800 (b) 48 (c) 480
  24. 24.Best estimate of 5474 ÷ 76? (a) 6800 (b) 68 (c) 680
  25. 25.Best estimate of 764 ÷ 29? (a) 2500 (b) 25 (c) 250
  26. 26.Best estimate of 1196 ÷ 26? (a) 4000 (b) 40 (c) 400
  27. 27.√80 to 1 decimal place? (a) 8.9 (b) 9.0 (c) 9.1 (d) 8.8
  28. 28.√38 to 1 decimal place? (a) 6.4 (b) 6.2 (c) 6.1 (d) 6.3
  29. 29.√58 to 1 decimal place? (a) 7.4 (b) 7.5 (c) 7.3 (d) 7.6
  30. 30.Best estimate of 1253 ÷ 44? (a) 31 (b) 310 (c) 3100
  31. 31.Best estimate of 1777 ÷ 61? (a) 300 (b) 30 (c) 3000
  32. 32.√55 to 1 decimal place? (a) 7.2 (b) 7.5 (c) 7.3 (d) 7.4
  33. 33.√74 to 1 decimal place? (a) 8.6 (b) 8.5 (c) 8.7 (d) 8.8
  34. 34.√59 to 1 decimal place? (a) 7.7 (b) 7.6 (c) 7.5 (d) 7.8
  35. 35.Best estimate of 2414 ÷ 26? (a) 8000 (b) 80 (c) 800
  36. 36.√37 to 1 decimal place? (a) 5.8 (b) 6.1 (c) 5.9 (d) 6.0
  37. 37.Best estimate of 1635 ÷ 77? (a) 200 (b) 20 (c) 2000
  38. 38.Best estimate of 4688 ÷ 79? (a) 590 (b) 5900 (c) 59
  39. 39.√50 to 1 decimal place? (a) 7.1 (b) 7.4 (c) 7.2 (d) 7.3
  40. 40.Best estimate of 7012 ÷ 84? (a) 8800 (b) 88 (c) 880

Answer key

  1. 6.9
  2. 5.8
  3. 82
  4. 35
  5. 105
  6. 67
  7. 62
  8. 9.2
  9. 9.8
  10. 9.5
  11. 57
  12. 67
  13. 8.9
  14. 71
  15. 5.3
  16. 8.4
  17. 4.8
  18. 5.7
  19. 88
  20. 74
  21. 42
  22. 34
  23. 48
  24. 68
  25. 25
  26. 40
  27. 8.9
  28. 6.2
  29. 7.6
  30. 31
  31. 30
  32. 7.4
  33. 8.6
  34. 7.7
  35. 80
  36. 6.1
  37. 20
  38. 59
  39. 7.1
  40. 88

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