← Estimate divisions and square roots lesson New set →

Estimating Square Roots and Division Worksheet

Mental maths lesson 27: Estimate divisions and square roots · Set 16 · 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) 6.7 (b) 6.6 (c) 6.9 (d) 6.8
  2. 2.Best estimate of 1187 ÷ 84? (a) 15 (b) 1500 (c) 150
  3. 3.Best estimate of 1349 ÷ 39? (a) 3400 (b) 34 (c) 340
  4. 4.Best estimate of 4952 ÷ 64? (a) 83 (b) 830 (c) 8300
  5. 5.Best estimate of 3754 ÷ 82? (a) 47 (b) 470 (c) 4700
  6. 6.Best estimate of 1803 ÷ 86? (a) 200 (b) 2000 (c) 20
  7. 7.√48 to 1 decimal place? (a) 6.6 (b) 6.7 (c) 6.8 (d) 6.9
  8. 8.Best estimate of 2138 ÷ 43? (a) 5300 (b) 53 (c) 530
  9. 9.Best estimate of 905 ÷ 68? (a) 13 (b) 1300 (c) 130
  10. 10.√92 to 1 decimal place? (a) 9.7 (b) 9.8 (c) 9.6 (d) 9.9
  11. 11.Best estimate of 2953 ÷ 39? (a) 74 (b) 740 (c) 7400
  12. 12.√87 to 1 decimal place? (a) 9.4 (b) 9.6 (c) 9.3 (d) 9.5
  13. 13.Best estimate of 2259 ÷ 58? (a) 380 (b) 3800 (c) 38
  14. 14.Best estimate of 4210 ÷ 82? (a) 5300 (b) 530 (c) 53
  15. 15.√22 to 1 decimal place? (a) 4.7 (b) 4.8 (c) 4.6 (d) 4.5
  16. 16.Best estimate of 547 ÷ 26? (a) 1800 (b) 18 (c) 180
  17. 17.√98 to 1 decimal place? (a) 10.1 (b) 10.0 (c) 9.9 (d) 9.8
  18. 18.Best estimate of 2201 ÷ 36? (a) 5500 (b) 550 (c) 55
  19. 19.Best estimate of 3027 ÷ 34? (a) 1010 (b) 101 (c) 10100
  20. 20.Best estimate of 1098 ÷ 66? (a) 16 (b) 160 (c) 1600
  21. 21.√26 to 1 decimal place? (a) 5.0 (b) 5.1 (c) 4.9 (d) 4.8
  22. 22.Best estimate of 7380 ÷ 78? (a) 9200 (b) 920 (c) 92
  23. 23.Best estimate of 746 ÷ 37? (a) 1900 (b) 19 (c) 190
  24. 24.Best estimate of 1137 ÷ 22? (a) 5700 (b) 57 (c) 570
  25. 25.Best estimate of 4500 ÷ 82? (a) 5600 (b) 560 (c) 56
  26. 26.√88 to 1 decimal place? (a) 9.4 (b) 9.3 (c) 9.5 (d) 9.6
  27. 27.Best estimate of 2290 ÷ 28? (a) 7600 (b) 76 (c) 760
  28. 28.Best estimate of 1858 ÷ 88? (a) 210 (b) 21 (c) 2100
  29. 29.Best estimate of 2805 ÷ 56? (a) 4700 (b) 470 (c) 47
  30. 30.Best estimate of 1850 ÷ 37? (a) 46 (b) 4600 (c) 460
  31. 31.√69 to 1 decimal place? (a) 8.4 (b) 8.3 (c) 8.1 (d) 8.2
  32. 32.Best estimate of 1488 ÷ 69? (a) 210 (b) 2100 (c) 21
  33. 33.√66 to 1 decimal place? (a) 8.0 (b) 8.1 (c) 7.9 (d) 7.8
  34. 34.√37 to 1 decimal place? (a) 6.2 (b) 5.9 (c) 6.0 (d) 6.1
  35. 35.Best estimate of 320 ÷ 22? (a) 16 (b) 1600 (c) 160
  36. 36.Best estimate of 6000 ÷ 67? (a) 86 (b) 860 (c) 8600
  37. 37.√50 to 1 decimal place? (a) 7.4 (b) 7.3 (c) 7.1 (d) 7.2
  38. 38.Best estimate of 2706 ÷ 46? (a) 540 (b) 54 (c) 5400
  39. 39.Best estimate of 6680 ÷ 71? (a) 950 (b) 9500 (c) 95
  40. 40.Best estimate of 2663 ÷ 48? (a) 53 (b) 5300 (c) 530

Answer key

  1. 6.9
  2. 15
  3. 34
  4. 83
  5. 47
  6. 20
  7. 6.9
  8. 53
  9. 13
  10. 9.6
  11. 74
  12. 9.3
  13. 38
  14. 53
  15. 4.7
  16. 18
  17. 9.9
  18. 55
  19. 101
  20. 16
  21. 5.1
  22. 92
  23. 19
  24. 57
  25. 56
  26. 9.4
  27. 76
  28. 21
  29. 47
  30. 46
  31. 8.3
  32. 21
  33. 8.1
  34. 6.1
  35. 16
  36. 86
  37. 7.1
  38. 54
  39. 95
  40. 53

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