← Estimate divisions and square roots lesson New set →

Estimating Square Roots and Division Worksheet

Mental maths lesson 27: Estimate divisions and square roots · Set 982 · 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 5274 ÷ 67? (a) 7500 (b) 750 (c) 75
  2. 2.√75 to 1 decimal place? (a) 8.7 (b) 8.4 (c) 8.6 (d) 8.5
  3. 3.Best estimate of 1551 ÷ 36? (a) 390 (b) 39 (c) 3900
  4. 4.Best estimate of 6281 ÷ 66? (a) 9000 (b) 90 (c) 900
  5. 5.√89 to 1 decimal place? (a) 9.5 (b) 9.3 (c) 9.2 (d) 9.4
  6. 6.Best estimate of 4831 ÷ 74? (a) 6900 (b) 69 (c) 690
  7. 7.Best estimate of 1952 ÷ 42? (a) 49 (b) 4900 (c) 490
  8. 8.√94 to 1 decimal place? (a) 9.6 (b) 9.5 (c) 9.8 (d) 9.7
  9. 9.√69 to 1 decimal place? (a) 8.6 (b) 8.5 (c) 8.3 (d) 8.4
  10. 10.Best estimate of 6207 ÷ 67? (a) 890 (b) 89 (c) 8900
  11. 11.Best estimate of 4978 ÷ 64? (a) 8300 (b) 830 (c) 83
  12. 12.Best estimate of 2409 ÷ 43? (a) 6000 (b) 60 (c) 600
  13. 13.Best estimate of 2454 ÷ 42? (a) 6100 (b) 61 (c) 610
  14. 14.Best estimate of 2730 ÷ 36? (a) 68 (b) 680 (c) 6800
  15. 15.Best estimate of 1165 ÷ 51? (a) 2300 (b) 23 (c) 230
  16. 16.√26 to 1 decimal place? (a) 5.4 (b) 5.1 (c) 5.2 (d) 5.3
  17. 17.Best estimate of 5174 ÷ 67? (a) 740 (b) 7400 (c) 74
  18. 18.Best estimate of 1685 ÷ 88? (a) 1900 (b) 190 (c) 19
  19. 19.Best estimate of 4424 ÷ 67? (a) 630 (b) 63 (c) 6300
  20. 20.√44 to 1 decimal place? (a) 6.6 (b) 6.4 (c) 6.5 (d) 6.7
  21. 21.Best estimate of 683 ÷ 52? (a) 140 (b) 1400 (c) 14
  22. 22.Best estimate of 1787 ÷ 76? (a) 22 (b) 2200 (c) 220
  23. 23.Best estimate of 4875 ÷ 83? (a) 61 (b) 6100 (c) 610
  24. 24.√55 to 1 decimal place? (a) 7.3 (b) 7.2 (c) 7.5 (d) 7.4
  25. 25.Best estimate of 1178 ÷ 37? (a) 29 (b) 290 (c) 2900
  26. 26.Best estimate of 1274 ÷ 28? (a) 4200 (b) 42 (c) 420
  27. 27.√83 to 1 decimal place? (a) 9.1 (b) 8.8 (c) 8.9 (d) 9.0
  28. 28.√92 to 1 decimal place? (a) 9.5 (b) 9.6 (c) 9.7 (d) 9.8
  29. 29.Best estimate of 2270 ÷ 36? (a) 570 (b) 5700 (c) 57
  30. 30.Best estimate of 5639 ÷ 82? (a) 700 (b) 70 (c) 7000
  31. 31.Best estimate of 4855 ÷ 72? (a) 6900 (b) 69 (c) 690
  32. 32.√67 to 1 decimal place? (a) 8.1 (b) 8.2 (c) 8.0 (d) 7.9
  33. 33.√61 to 1 decimal place? (a) 7.9 (b) 8.1 (c) 7.8 (d) 8.0
  34. 34.Best estimate of 2353 ÷ 61? (a) 390 (b) 39 (c) 3900
  35. 35.Best estimate of 3297 ÷ 42? (a) 8200 (b) 820 (c) 82
  36. 36.√52 to 1 decimal place? (a) 7.2 (b) 7.3 (c) 7.5 (d) 7.4
  37. 37.Best estimate of 1961 ÷ 59? (a) 33 (b) 3300 (c) 330
  38. 38.√85 to 1 decimal place? (a) 9.4 (b) 9.3 (c) 9.2 (d) 9.5
  39. 39.Best estimate of 445 ÷ 24? (a) 2200 (b) 220 (c) 22
  40. 40.Best estimate of 4894 ÷ 83? (a) 6100 (b) 610 (c) 61

Answer key

  1. 75
  2. 8.7
  3. 39
  4. 90
  5. 9.4
  6. 69
  7. 49
  8. 9.7
  9. 8.3
  10. 89
  11. 83
  12. 60
  13. 61
  14. 68
  15. 23
  16. 5.1
  17. 74
  18. 19
  19. 63
  20. 6.6
  21. 14
  22. 22
  23. 61
  24. 7.4
  25. 29
  26. 42
  27. 9.1
  28. 9.6
  29. 57
  30. 70
  31. 69
  32. 8.2
  33. 7.8
  34. 39
  35. 82
  36. 7.2
  37. 33
  38. 9.2
  39. 22
  40. 61

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