← Estimate divisions and square roots lesson New set →

Estimating Square Roots and Division Worksheet

Mental maths lesson 27: Estimate divisions and square roots · Set 794 · 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.√43 to 1 decimal place? (a) 6.3 (b) 6.5 (c) 6.6 (d) 6.4
  2. 2.Best estimate of 3413 ÷ 56? (a) 570 (b) 57 (c) 5700
  3. 3.Best estimate of 2454 ÷ 84? (a) 310 (b) 31 (c) 3100
  4. 4.Best estimate of 2664 ÷ 49? (a) 530 (b) 5300 (c) 53
  5. 5.Best estimate of 1146 ÷ 89? (a) 130 (b) 13 (c) 1300
  6. 6.√23 to 1 decimal place? (a) 4.9 (b) 4.8 (c) 4.6 (d) 4.7
  7. 7.Best estimate of 3079 ÷ 34? (a) 103 (b) 1030 (c) 10300
  8. 8.Best estimate of 2677 ÷ 77? (a) 3300 (b) 330 (c) 33
  9. 9.√32 to 1 decimal place? (a) 5.8 (b) 5.5 (c) 5.7 (d) 5.6
  10. 10.√80 to 1 decimal place? (a) 9.1 (b) 8.8 (c) 9.0 (d) 8.9
  11. 11.√34 to 1 decimal place? (a) 5.8 (b) 5.6 (c) 5.7 (d) 5.9
  12. 12.Best estimate of 5531 ÷ 59? (a) 9200 (b) 920 (c) 92
  13. 13.Best estimate of 2267 ÷ 37? (a) 5700 (b) 570 (c) 57
  14. 14.√46 to 1 decimal place? (a) 6.9 (b) 6.8 (c) 6.6 (d) 6.7
  15. 15.Best estimate of 7818 ÷ 84? (a) 980 (b) 9800 (c) 98
  16. 16.√37 to 1 decimal place? (a) 6.2 (b) 6.1 (c) 6.4 (d) 6.3
  17. 17.√77 to 1 decimal place? (a) 8.8 (b) 9.0 (c) 8.7 (d) 8.9
  18. 18.√65 to 1 decimal place? (a) 8.2 (b) 8.1 (c) 8.0 (d) 8.3
  19. 19.Best estimate of 3303 ÷ 38? (a) 83 (b) 8300 (c) 830
  20. 20.√88 to 1 decimal place? (a) 9.2 (b) 9.3 (c) 9.4 (d) 9.1
  21. 21.Best estimate of 2162 ÷ 28? (a) 7200 (b) 720 (c) 72
  22. 22.√40 to 1 decimal place? (a) 6.4 (b) 6.3 (c) 6.5 (d) 6.2
  23. 23.√35 to 1 decimal place? (a) 5.8 (b) 6.1 (c) 6.0 (d) 5.9
  24. 24.Best estimate of 950 ÷ 72? (a) 140 (b) 14 (c) 1400
  25. 25.Best estimate of 6837 ÷ 86? (a) 760 (b) 7600 (c) 76
  26. 26.Best estimate of 2296 ÷ 33? (a) 77 (b) 7700 (c) 770
  27. 27.Best estimate of 7033 ÷ 78? (a) 8800 (b) 880 (c) 88
  28. 28.√53 to 1 decimal place? (a) 7.4 (b) 7.5 (c) 7.3 (d) 7.2
  29. 29.Best estimate of 4028 ÷ 82? (a) 5000 (b) 50 (c) 500
  30. 30.√31 to 1 decimal place? (a) 5.6 (b) 5.8 (c) 5.9 (d) 5.7
  31. 31.Best estimate of 2464 ÷ 71? (a) 35 (b) 350 (c) 3500
  32. 32.√92 to 1 decimal place? (a) 9.5 (b) 9.6 (c) 9.3 (d) 9.4
  33. 33.Best estimate of 5527 ÷ 64? (a) 9200 (b) 92 (c) 920
  34. 34.√38 to 1 decimal place? (a) 6.3 (b) 6.2 (c) 6.0 (d) 6.1
  35. 35.Best estimate of 2331 ÷ 26? (a) 7800 (b) 78 (c) 780
  36. 36.Best estimate of 675 ÷ 21? (a) 340 (b) 3400 (c) 34
  37. 37.√50 to 1 decimal place? (a) 7.0 (b) 7.1 (c) 6.8 (d) 6.9
  38. 38.√58 to 1 decimal place? (a) 7.5 (b) 7.6 (c) 7.8 (d) 7.7
  39. 39.√61 to 1 decimal place? (a) 7.9 (b) 7.7 (c) 8.0 (d) 7.8
  40. 40.Best estimate of 7052 ÷ 76? (a) 880 (b) 8800 (c) 88

Answer key

  1. 6.6
  2. 57
  3. 31
  4. 53
  5. 13
  6. 4.8
  7. 103
  8. 33
  9. 5.7
  10. 8.9
  11. 5.8
  12. 92
  13. 57
  14. 6.8
  15. 98
  16. 6.1
  17. 8.8
  18. 8.1
  19. 83
  20. 9.4
  21. 72
  22. 6.3
  23. 5.9
  24. 14
  25. 76
  26. 77
  27. 88
  28. 7.3
  29. 50
  30. 5.6
  31. 35
  32. 9.6
  33. 92
  34. 6.2
  35. 78
  36. 34
  37. 7.1
  38. 7.6
  39. 7.8
  40. 88

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