← Estimate divisions and square roots lesson New set →

Estimating Square Roots and Division Worksheet

Mental maths lesson 27: Estimate divisions and square roots · Set 474 · 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.√67 to 1 decimal place? (a) 8.2 (b) 8.1 (c) 8.3 (d) 8.0
  2. 2.Best estimate of 5257 ÷ 59? (a) 88 (b) 8800 (c) 880
  3. 3.√37 to 1 decimal place? (a) 6.3 (b) 6.0 (c) 6.1 (d) 6.2
  4. 4.Best estimate of 2248 ÷ 61? (a) 37 (b) 3700 (c) 370
  5. 5.Best estimate of 1925 ÷ 22? (a) 96 (b) 9600 (c) 960
  6. 6.Best estimate of 882 ÷ 32? (a) 290 (b) 29 (c) 2900
  7. 7.√40 to 1 decimal place? (a) 6.5 (b) 6.4 (c) 6.6 (d) 6.3
  8. 8.Best estimate of 435 ÷ 34? (a) 150 (b) 15 (c) 1500
  9. 9.√76 to 1 decimal place? (a) 8.8 (b) 8.5 (c) 8.7 (d) 8.6
  10. 10.Best estimate of 5135 ÷ 76? (a) 640 (b) 64 (c) 6400
  11. 11.√23 to 1 decimal place? (a) 5.0 (b) 4.7 (c) 4.8 (d) 4.9
  12. 12.Best estimate of 3290 ÷ 84? (a) 41 (b) 410 (c) 4100
  13. 13.Best estimate of 1470 ÷ 36? (a) 37 (b) 370 (c) 3700
  14. 14.√78 to 1 decimal place? (a) 8.8 (b) 9.0 (c) 8.9 (d) 8.7
  15. 15.Best estimate of 2358 ÷ 79? (a) 2900 (b) 290 (c) 29
  16. 16.√96 to 1 decimal place? (a) 9.8 (b) 9.7 (c) 9.9 (d) 10.0
  17. 17.Best estimate of 3318 ÷ 38? (a) 830 (b) 8300 (c) 83
  18. 18.Best estimate of 2466 ÷ 32? (a) 8200 (b) 82 (c) 820
  19. 19.Best estimate of 758 ÷ 26? (a) 25 (b) 2500 (c) 250
  20. 20.√24 to 1 decimal place? (a) 4.7 (b) 4.8 (c) 4.9 (d) 5.0
  21. 21.Best estimate of 5504 ÷ 69? (a) 79 (b) 790 (c) 7900
  22. 22.Best estimate of 2131 ÷ 59? (a) 3600 (b) 360 (c) 36
  23. 23.Best estimate of 2771 ÷ 34? (a) 9200 (b) 920 (c) 92
  24. 24.Best estimate of 765 ÷ 36? (a) 190 (b) 19 (c) 1900
  25. 25.Best estimate of 922 ÷ 22? (a) 4600 (b) 46 (c) 460
  26. 26.Best estimate of 559 ÷ 23? (a) 280 (b) 28 (c) 2800
  27. 27.√65 to 1 decimal place? (a) 8.3 (b) 8.1 (c) 8.0 (d) 8.2
  28. 28.Best estimate of 956 ÷ 58? (a) 160 (b) 1600 (c) 16
  29. 29.√26 to 1 decimal place? (a) 4.9 (b) 5.1 (c) 5.0 (d) 4.8
  30. 30.Best estimate of 1397 ÷ 43? (a) 350 (b) 35 (c) 3500
  31. 31.Best estimate of 1345 ÷ 23? (a) 67 (b) 6700 (c) 670
  32. 32.√20 to 1 decimal place? (a) 4.4 (b) 4.7 (c) 4.5 (d) 4.6
  33. 33.Best estimate of 3760 ÷ 49? (a) 75 (b) 7500 (c) 750
  34. 34.√58 to 1 decimal place? (a) 7.7 (b) 7.6 (c) 7.8 (d) 7.9
  35. 35.√89 to 1 decimal place? (a) 9.6 (b) 9.5 (c) 9.4 (d) 9.3
  36. 36.√80 to 1 decimal place? (a) 8.8 (b) 9.1 (c) 8.9 (d) 9.0
  37. 37.√34 to 1 decimal place? (a) 5.8 (b) 5.7 (c) 5.9 (d) 6.0
  38. 38.Best estimate of 5446 ÷ 76? (a) 6800 (b) 680 (c) 68
  39. 39.Best estimate of 3888 ÷ 76? (a) 490 (b) 49 (c) 4900
  40. 40.√41 to 1 decimal place? (a) 6.5 (b) 6.4 (c) 6.3 (d) 6.2

Answer key

  1. 8.2
  2. 88
  3. 6.1
  4. 37
  5. 96
  6. 29
  7. 6.3
  8. 15
  9. 8.7
  10. 64
  11. 4.8
  12. 41
  13. 37
  14. 8.8
  15. 29
  16. 9.8
  17. 83
  18. 82
  19. 25
  20. 4.9
  21. 79
  22. 36
  23. 92
  24. 19
  25. 46
  26. 28
  27. 8.1
  28. 16
  29. 5.1
  30. 35
  31. 67
  32. 4.5
  33. 75
  34. 7.6
  35. 9.4
  36. 8.9
  37. 5.8
  38. 68
  39. 49
  40. 6.4

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