← Estimate divisions and square roots lesson New set →

Estimating Square Roots and Division Worksheet

Mental maths lesson 27: Estimate divisions and square roots · Set 4 · 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 2532 ÷ 87? (a) 28 (b) 280 (c) 2800
  2. 2.√66 to 1 decimal place? (a) 8.2 (b) 8.3 (c) 8.0 (d) 8.1
  3. 3.√89 to 1 decimal place? (a) 9.4 (b) 9.6 (c) 9.5 (d) 9.7
  4. 4.√70 to 1 decimal place? (a) 8.4 (b) 8.3 (c) 8.5 (d) 8.6
  5. 5.√61 to 1 decimal place? (a) 7.7 (b) 7.6 (c) 7.5 (d) 7.8
  6. 6.Best estimate of 2913 ÷ 69? (a) 420 (b) 4200 (c) 42
  7. 7.Best estimate of 6715 ÷ 76? (a) 84 (b) 8400 (c) 840
  8. 8.√20 to 1 decimal place? (a) 4.5 (b) 4.7 (c) 4.6 (d) 4.4
  9. 9.Best estimate of 3301 ÷ 36? (a) 8300 (b) 83 (c) 830
  10. 10.Best estimate of 3211 ÷ 84? (a) 40 (b) 400 (c) 4000
  11. 11.√35 to 1 decimal place? (a) 6.0 (b) 5.9 (c) 6.2 (d) 6.1
  12. 12.√29 to 1 decimal place? (a) 5.1 (b) 5.2 (c) 5.3 (d) 5.4
  13. 13.√92 to 1 decimal place? (a) 9.7 (b) 9.5 (c) 9.6 (d) 9.8
  14. 14.Best estimate of 3805 ÷ 84? (a) 480 (b) 48 (c) 4800
  15. 15.Best estimate of 4955 ÷ 68? (a) 71 (b) 7100 (c) 710
  16. 16.Best estimate of 3324 ÷ 42? (a) 8300 (b) 83 (c) 830
  17. 17.Best estimate of 1181 ÷ 48? (a) 2400 (b) 24 (c) 240
  18. 18.Best estimate of 608 ÷ 29? (a) 2000 (b) 20 (c) 200
  19. 19.√83 to 1 decimal place? (a) 9.3 (b) 9.1 (c) 9.0 (d) 9.2
  20. 20.√69 to 1 decimal place? (a) 8.5 (b) 8.3 (c) 8.6 (d) 8.4
  21. 21.Best estimate of 845 ÷ 24? (a) 4200 (b) 42 (c) 420
  22. 22.Best estimate of 5032 ÷ 74? (a) 720 (b) 72 (c) 7200
  23. 23.√37 to 1 decimal place? (a) 6.1 (b) 6.3 (c) 6.2 (d) 6.4
  24. 24.√77 to 1 decimal place? (a) 8.7 (b) 9.0 (c) 8.8 (d) 8.9
  25. 25.√23 to 1 decimal place? (a) 4.8 (b) 4.6 (c) 4.7 (d) 4.5
  26. 26.√27 to 1 decimal place? (a) 5.2 (b) 5.1 (c) 5.0 (d) 5.3
  27. 27.Best estimate of 2267 ÷ 29? (a) 760 (b) 76 (c) 7600
  28. 28.√80 to 1 decimal place? (a) 9.0 (b) 9.2 (c) 9.1 (d) 8.9
  29. 29.Best estimate of 594 ÷ 27? (a) 2000 (b) 20 (c) 200
  30. 30.√71 to 1 decimal place? (a) 8.4 (b) 8.6 (c) 8.5 (d) 8.3
  31. 31.Best estimate of 7305 ÷ 82? (a) 910 (b) 9100 (c) 91
  32. 32.Best estimate of 2084 ÷ 32? (a) 690 (b) 69 (c) 6900
  33. 33.√84 to 1 decimal place? (a) 9.1 (b) 9.2 (c) 9.0 (d) 8.9
  34. 34.Best estimate of 711 ÷ 36? (a) 1800 (b) 18 (c) 180
  35. 35.Best estimate of 3347 ÷ 69? (a) 480 (b) 4800 (c) 48
  36. 36.Best estimate of 1285 ÷ 62? (a) 2100 (b) 21 (c) 210
  37. 37.√82 to 1 decimal place? (a) 8.9 (b) 8.8 (c) 9.1 (d) 9.0
  38. 38.Best estimate of 7273 ÷ 89? (a) 8100 (b) 810 (c) 81
  39. 39.Best estimate of 1166 ÷ 58? (a) 190 (b) 1900 (c) 19
  40. 40.Best estimate of 663 ÷ 43? (a) 170 (b) 17 (c) 1700

Answer key

  1. 28
  2. 8.1
  3. 9.4
  4. 8.4
  5. 7.8
  6. 42
  7. 84
  8. 4.5
  9. 83
  10. 40
  11. 5.9
  12. 5.4
  13. 9.6
  14. 48
  15. 71
  16. 83
  17. 24
  18. 20
  19. 9.1
  20. 8.3
  21. 42
  22. 72
  23. 6.1
  24. 8.8
  25. 4.8
  26. 5.2
  27. 76
  28. 8.9
  29. 20
  30. 8.4
  31. 91
  32. 69
  33. 9.2
  34. 18
  35. 48
  36. 21
  37. 9.1
  38. 81
  39. 19
  40. 17

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