← Estimate divisions and square roots lesson New set →

Estimating Square Roots and Division Worksheet

Mental maths lesson 27: Estimate divisions and square roots · Set 905 · 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.√96 to 1 decimal place? (a) 9.9 (b) 9.7 (c) 9.6 (d) 9.8
  2. 2.√43 to 1 decimal place? (a) 6.9 (b) 6.7 (c) 6.6 (d) 6.8
  3. 3.√82 to 1 decimal place? (a) 9.1 (b) 9.0 (c) 8.9 (d) 8.8
  4. 4.Best estimate of 1983 ÷ 76? (a) 2500 (b) 250 (c) 25
  5. 5.Best estimate of 2460 ÷ 63? (a) 410 (b) 4100 (c) 41
  6. 6.√32 to 1 decimal place? (a) 5.8 (b) 5.9 (c) 6.0 (d) 5.7
  7. 7.√27 to 1 decimal place? (a) 5.2 (b) 5.1 (c) 5.4 (d) 5.3
  8. 8.Best estimate of 2306 ÷ 49? (a) 46 (b) 4600 (c) 460
  9. 9.√94 to 1 decimal place? (a) 9.9 (b) 9.8 (c) 10.0 (d) 9.7
  10. 10.√24 to 1 decimal place? (a) 4.7 (b) 4.9 (c) 4.8 (d) 4.6
  11. 11.√77 to 1 decimal place? (a) 8.8 (b) 8.9 (c) 8.7 (d) 9.0
  12. 12.Best estimate of 2672 ÷ 31? (a) 8900 (b) 89 (c) 890
  13. 13.√50 to 1 decimal place? (a) 7.2 (b) 6.9 (c) 7.0 (d) 7.1
  14. 14.Best estimate of 1930 ÷ 71? (a) 2800 (b) 28 (c) 280
  15. 15.√29 to 1 decimal place? (a) 5.3 (b) 5.5 (c) 5.4 (d) 5.2
  16. 16.√80 to 1 decimal place? (a) 8.8 (b) 9.1 (c) 8.9 (d) 9.0
  17. 17.√26 to 1 decimal place? (a) 5.3 (b) 5.1 (c) 5.0 (d) 5.2
  18. 18.Best estimate of 1754 ÷ 29? (a) 5800 (b) 58 (c) 580
  19. 19.Best estimate of 1000 ÷ 41? (a) 250 (b) 2500 (c) 25
  20. 20.Best estimate of 3028 ÷ 77? (a) 380 (b) 3800 (c) 38
  21. 21.Best estimate of 3683 ÷ 51? (a) 7400 (b) 740 (c) 74
  22. 22.Best estimate of 2241 ÷ 61? (a) 370 (b) 3700 (c) 37
  23. 23.√31 to 1 decimal place? (a) 5.7 (b) 5.6 (c) 5.8 (d) 5.9
  24. 24.Best estimate of 4258 ÷ 87? (a) 4700 (b) 47 (c) 470
  25. 25.√72 to 1 decimal place? (a) 8.5 (b) 8.4 (c) 8.6 (d) 8.3
  26. 26.√48 to 1 decimal place? (a) 7.2 (b) 7.1 (c) 7.0 (d) 6.9
  27. 27.Best estimate of 3096 ÷ 52? (a) 620 (b) 62 (c) 6200
  28. 28.√35 to 1 decimal place? (a) 5.8 (b) 5.7 (c) 5.9 (d) 5.6
  29. 29.Best estimate of 1524 ÷ 69? (a) 22 (b) 220 (c) 2200
  30. 30.Best estimate of 1728 ÷ 21? (a) 86 (b) 860 (c) 8600
  31. 31.√67 to 1 decimal place? (a) 8.1 (b) 8.0 (c) 8.2 (d) 8.3
  32. 32.√46 to 1 decimal place? (a) 6.6 (b) 6.7 (c) 6.9 (d) 6.8
  33. 33.√62 to 1 decimal place? (a) 7.9 (b) 7.6 (c) 7.8 (d) 7.7
  34. 34.√42 to 1 decimal place? (a) 6.4 (b) 6.3 (c) 6.5 (d) 6.2
  35. 35.Best estimate of 2952 ÷ 46? (a) 590 (b) 59 (c) 5900
  36. 36.Best estimate of 6093 ÷ 76? (a) 76 (b) 760 (c) 7600
  37. 37.Best estimate of 3260 ÷ 68? (a) 47 (b) 470 (c) 4700
  38. 38.Best estimate of 5281 ÷ 89? (a) 59 (b) 5900 (c) 590
  39. 39.Best estimate of 7732 ÷ 82? (a) 970 (b) 97 (c) 9700
  40. 40.√53 to 1 decimal place? (a) 7.2 (b) 7.3 (c) 7.4 (d) 7.1

Answer key

  1. 9.8
  2. 6.6
  3. 9.1
  4. 25
  5. 41
  6. 5.7
  7. 5.2
  8. 46
  9. 9.7
  10. 4.9
  11. 8.8
  12. 89
  13. 7.1
  14. 28
  15. 5.4
  16. 8.9
  17. 5.1
  18. 58
  19. 25
  20. 38
  21. 74
  22. 37
  23. 5.6
  24. 47
  25. 8.5
  26. 6.9
  27. 62
  28. 5.9
  29. 22
  30. 86
  31. 8.2
  32. 6.8
  33. 7.9
  34. 6.5
  35. 59
  36. 76
  37. 47
  38. 59
  39. 97
  40. 7.3

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