← Estimate divisions and square roots lesson New set →

Estimating Square Roots and Division Worksheet

Mental maths lesson 27: Estimate divisions and square roots · Set 500 · 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 2176 ÷ 26? (a) 7300 (b) 730 (c) 73
  2. 2.Best estimate of 2999 ÷ 49? (a) 600 (b) 6000 (c) 60
  3. 3.Best estimate of 2976 ÷ 84? (a) 370 (b) 3700 (c) 37
  4. 4.Best estimate of 1408 ÷ 36? (a) 3500 (b) 35 (c) 350
  5. 5.Best estimate of 6004 ÷ 77? (a) 75 (b) 7500 (c) 750
  6. 6.Best estimate of 1742 ÷ 49? (a) 3500 (b) 350 (c) 35
  7. 7.Best estimate of 4148 ÷ 73? (a) 590 (b) 59 (c) 5900
  8. 8.√26 to 1 decimal place? (a) 4.9 (b) 5.0 (c) 5.1 (d) 4.8
  9. 9.Best estimate of 2282 ÷ 32? (a) 76 (b) 7600 (c) 760
  10. 10.√34 to 1 decimal place? (a) 5.7 (b) 5.6 (c) 5.9 (d) 5.8
  11. 11.Best estimate of 1919 ÷ 39? (a) 480 (b) 48 (c) 4800
  12. 12.Best estimate of 7302 ÷ 84? (a) 91 (b) 910 (c) 9100
  13. 13.Best estimate of 2425 ÷ 37? (a) 61 (b) 6100 (c) 610
  14. 14.Best estimate of 1007 ÷ 69? (a) 1400 (b) 140 (c) 14
  15. 15.Best estimate of 2241 ÷ 36? (a) 560 (b) 56 (c) 5600
  16. 16.Best estimate of 7709 ÷ 86? (a) 860 (b) 86 (c) 8600
  17. 17.√27 to 1 decimal place? (a) 5.4 (b) 5.5 (c) 5.2 (d) 5.3
  18. 18.Best estimate of 5513 ÷ 81? (a) 690 (b) 69 (c) 6900
  19. 19.Best estimate of 2056 ÷ 69? (a) 2900 (b) 29 (c) 290
  20. 20.√55 to 1 decimal place? (a) 7.3 (b) 7.2 (c) 7.4 (d) 7.5
  21. 21.Best estimate of 812 ÷ 57? (a) 14 (b) 1400 (c) 140
  22. 22.Best estimate of 7204 ÷ 81? (a) 900 (b) 90 (c) 9000
  23. 23.Best estimate of 1722 ÷ 22? (a) 86 (b) 8600 (c) 860
  24. 24.√47 to 1 decimal place? (a) 6.8 (b) 6.9 (c) 7.1 (d) 7.0
  25. 25.Best estimate of 1062 ÷ 39? (a) 27 (b) 2700 (c) 270
  26. 26.Best estimate of 2555 ÷ 72? (a) 3700 (b) 37 (c) 370
  27. 27.Best estimate of 2187 ÷ 26? (a) 7300 (b) 730 (c) 73
  28. 28.√32 to 1 decimal place? (a) 5.4 (b) 5.5 (c) 5.7 (d) 5.6
  29. 29.Best estimate of 753 ÷ 34? (a) 25 (b) 2500 (c) 250
  30. 30.Best estimate of 3270 ÷ 83? (a) 410 (b) 41 (c) 4100
  31. 31.Best estimate of 3311 ÷ 37? (a) 830 (b) 83 (c) 8300
  32. 32.Best estimate of 535 ÷ 23? (a) 27 (b) 2700 (c) 270
  33. 33.√76 to 1 decimal place? (a) 8.7 (b) 8.5 (c) 8.8 (d) 8.6
  34. 34.√51 to 1 decimal place? (a) 7.2 (b) 7.3 (c) 7.4 (d) 7.1
  35. 35.√52 to 1 decimal place? (a) 7.1 (b) 7.0 (c) 7.2 (d) 7.3
  36. 36.Best estimate of 5116 ÷ 81? (a) 64 (b) 6400 (c) 640
  37. 37.Best estimate of 4824 ÷ 62? (a) 800 (b) 80 (c) 8000
  38. 38.Best estimate of 3307 ÷ 87? (a) 37 (b) 370 (c) 3700
  39. 39.√40 to 1 decimal place? (a) 6.1 (b) 6.3 (c) 6.4 (d) 6.2
  40. 40.Best estimate of 2413 ÷ 71? (a) 34 (b) 340 (c) 3400

Answer key

  1. 73
  2. 60
  3. 37
  4. 35
  5. 75
  6. 35
  7. 59
  8. 5.1
  9. 76
  10. 5.8
  11. 48
  12. 91
  13. 61
  14. 14
  15. 56
  16. 86
  17. 5.2
  18. 69
  19. 29
  20. 7.4
  21. 14
  22. 90
  23. 86
  24. 6.9
  25. 27
  26. 37
  27. 73
  28. 5.7
  29. 25
  30. 41
  31. 83
  32. 27
  33. 8.7
  34. 7.1
  35. 7.2
  36. 64
  37. 80
  38. 37
  39. 6.3
  40. 34

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