← Estimate divisions and square roots lesson New set →

Estimating Square Roots and Division Worksheet

Mental maths lesson 27: Estimate divisions and square roots · Set 789 · 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.√23 to 1 decimal place? (a) 5.0 (b) 5.1 (c) 4.8 (d) 4.9
  2. 2.Best estimate of 1210 ÷ 34? (a) 400 (b) 40 (c) 4000
  3. 3.√34 to 1 decimal place? (a) 5.7 (b) 5.6 (c) 5.5 (d) 5.8
  4. 4.√46 to 1 decimal place? (a) 7.0 (b) 6.9 (c) 6.8 (d) 6.7
  5. 5.Best estimate of 4664 ÷ 56? (a) 78 (b) 7800 (c) 780
  6. 6.√67 to 1 decimal place? (a) 8.0 (b) 8.2 (c) 8.1 (d) 8.3
  7. 7.Best estimate of 1509 ÷ 71? (a) 2200 (b) 220 (c) 22
  8. 8.Best estimate of 989 ÷ 77? (a) 1200 (b) 120 (c) 12
  9. 9.Best estimate of 3640 ÷ 52? (a) 730 (b) 7300 (c) 73
  10. 10.√40 to 1 decimal place? (a) 6.5 (b) 6.6 (c) 6.4 (d) 6.3
  11. 11.√80 to 1 decimal place? (a) 8.7 (b) 8.9 (c) 8.8 (d) 9.0
  12. 12.Best estimate of 5027 ÷ 59? (a) 84 (b) 8400 (c) 840
  13. 13.Best estimate of 2072 ÷ 24? (a) 1040 (b) 10400 (c) 104
  14. 14.Best estimate of 2002 ÷ 38? (a) 50 (b) 5000 (c) 500
  15. 15.Best estimate of 1818 ÷ 46? (a) 3600 (b) 360 (c) 36
  16. 16.Best estimate of 1405 ÷ 32? (a) 47 (b) 470 (c) 4700
  17. 17.Best estimate of 6229 ÷ 87? (a) 6900 (b) 69 (c) 690
  18. 18.Best estimate of 2918 ÷ 43? (a) 73 (b) 7300 (c) 730
  19. 19.Best estimate of 5089 ÷ 87? (a) 57 (b) 5700 (c) 570
  20. 20.√56 to 1 decimal place? (a) 7.5 (b) 7.3 (c) 7.4 (d) 7.2
  21. 21.Best estimate of 1555 ÷ 62? (a) 2600 (b) 26 (c) 260
  22. 22.√82 to 1 decimal place? (a) 8.9 (b) 9.0 (c) 9.1 (d) 8.8
  23. 23.Best estimate of 1857 ÷ 36? (a) 4600 (b) 460 (c) 46
  24. 24.Best estimate of 5048 ÷ 56? (a) 8400 (b) 840 (c) 84
  25. 25.Best estimate of 2622 ÷ 36? (a) 6600 (b) 660 (c) 66
  26. 26.Best estimate of 3706 ÷ 82? (a) 460 (b) 46 (c) 4600
  27. 27.Best estimate of 2771 ÷ 39? (a) 69 (b) 690 (c) 6900
  28. 28.Best estimate of 7422 ÷ 86? (a) 820 (b) 82 (c) 8200
  29. 29.√37 to 1 decimal place? (a) 6.0 (b) 5.9 (c) 6.1 (d) 5.8
  30. 30.√76 to 1 decimal place? (a) 8.5 (b) 8.8 (c) 8.7 (d) 8.6
  31. 31.√28 to 1 decimal place? (a) 5.5 (b) 5.2 (c) 5.3 (d) 5.4
  32. 32.Best estimate of 799 ÷ 34? (a) 270 (b) 2700 (c) 27
  33. 33.Best estimate of 746 ÷ 56? (a) 12 (b) 1200 (c) 120
  34. 34.Best estimate of 5669 ÷ 73? (a) 81 (b) 810 (c) 8100
  35. 35.√70 to 1 decimal place? (a) 8.5 (b) 8.2 (c) 8.3 (d) 8.4
  36. 36.Best estimate of 845 ÷ 26? (a) 2800 (b) 280 (c) 28
  37. 37.Best estimate of 2676 ÷ 33? (a) 8900 (b) 890 (c) 89
  38. 38.√32 to 1 decimal place? (a) 5.7 (b) 5.9 (c) 6.0 (d) 5.8
  39. 39.√71 to 1 decimal place? (a) 8.5 (b) 8.4 (c) 8.2 (d) 8.3
  40. 40.Best estimate of 328 ÷ 27? (a) 1100 (b) 110 (c) 11

Answer key

  1. 4.8
  2. 40
  3. 5.8
  4. 6.8
  5. 78
  6. 8.2
  7. 22
  8. 12
  9. 73
  10. 6.3
  11. 8.9
  12. 84
  13. 104
  14. 50
  15. 36
  16. 47
  17. 69
  18. 73
  19. 57
  20. 7.5
  21. 26
  22. 9.1
  23. 46
  24. 84
  25. 66
  26. 46
  27. 69
  28. 82
  29. 6.1
  30. 8.7
  31. 5.3
  32. 27
  33. 12
  34. 81
  35. 8.4
  36. 28
  37. 89
  38. 5.7
  39. 8.4
  40. 11

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