← Estimate divisions and square roots lesson New set →

Estimating Square Roots and Division Worksheet

Mental maths lesson 27: Estimate divisions and square roots · Set 594 · 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) 8.4 (c) 8.3 (d) 8.5
  2. 2.Best estimate of 1656 ÷ 51? (a) 330 (b) 33 (c) 3300
  3. 3.Best estimate of 4043 ÷ 77? (a) 510 (b) 5100 (c) 51
  4. 4.√40 to 1 decimal place? (a) 6.2 (b) 6.3 (c) 6.1 (d) 6.4
  5. 5.Best estimate of 1392 ÷ 58? (a) 2300 (b) 23 (c) 230
  6. 6.√50 to 1 decimal place? (a) 7.3 (b) 7.2 (c) 7.0 (d) 7.1
  7. 7.Best estimate of 1217 ÷ 23? (a) 61 (b) 610 (c) 6100
  8. 8.Best estimate of 3889 ÷ 81? (a) 490 (b) 4900 (c) 49
  9. 9.√82 to 1 decimal place? (a) 8.9 (b) 9.2 (c) 9.1 (d) 9.0
  10. 10.Best estimate of 5285 ÷ 62? (a) 880 (b) 88 (c) 8800
  11. 11.Best estimate of 6463 ÷ 73? (a) 9200 (b) 92 (c) 920
  12. 12.√87 to 1 decimal place? (a) 9.2 (b) 9.0 (c) 9.3 (d) 9.1
  13. 13.Best estimate of 4093 ÷ 56? (a) 68 (b) 6800 (c) 680
  14. 14.√23 to 1 decimal place? (a) 4.9 (b) 4.8 (c) 4.7 (d) 4.6
  15. 15.Best estimate of 4713 ÷ 86? (a) 520 (b) 5200 (c) 52
  16. 16.√22 to 1 decimal place? (a) 4.7 (b) 4.6 (c) 4.5 (d) 4.8
  17. 17.√75 to 1 decimal place? (a) 9.0 (b) 8.8 (c) 8.7 (d) 8.9
  18. 18.Best estimate of 1039 ÷ 41? (a) 26 (b) 260 (c) 2600
  19. 19.√58 to 1 decimal place? (a) 7.4 (b) 7.6 (c) 7.5 (d) 7.7
  20. 20.Best estimate of 4663 ÷ 76? (a) 58 (b) 580 (c) 5800
  21. 21.√37 to 1 decimal place? (a) 6.3 (b) 6.2 (c) 6.4 (d) 6.1
  22. 22.√71 to 1 decimal place? (a) 8.6 (b) 8.5 (c) 8.4 (d) 8.7
  23. 23.Best estimate of 508 ÷ 24? (a) 25 (b) 2500 (c) 250
  24. 24.√74 to 1 decimal place? (a) 8.6 (b) 8.8 (c) 8.9 (d) 8.7
  25. 25.Best estimate of 1509 ÷ 32? (a) 500 (b) 5000 (c) 50
  26. 26.√84 to 1 decimal place? (a) 9.2 (b) 9.3 (c) 9.4 (d) 9.5
  27. 27.Best estimate of 5549 ÷ 73? (a) 79 (b) 7900 (c) 790
  28. 28.Best estimate of 1767 ÷ 63? (a) 290 (b) 2900 (c) 29
  29. 29.Best estimate of 1162 ÷ 36? (a) 2900 (b) 29 (c) 290
  30. 30.Best estimate of 4383 ÷ 72? (a) 6300 (b) 630 (c) 63
  31. 31.Best estimate of 1904 ÷ 67? (a) 2700 (b) 27 (c) 270
  32. 32.Best estimate of 783 ÷ 22? (a) 3900 (b) 390 (c) 39
  33. 33.√96 to 1 decimal place? (a) 9.6 (b) 9.7 (c) 9.5 (d) 9.8
  34. 34.√63 to 1 decimal place? (a) 7.9 (b) 8.2 (c) 8.1 (d) 8.0
  35. 35.√94 to 1 decimal place? (a) 9.7 (b) 9.8 (c) 9.6 (d) 9.5
  36. 36.√88 to 1 decimal place? (a) 9.7 (b) 9.4 (c) 9.6 (d) 9.5
  37. 37.Best estimate of 2086 ÷ 86? (a) 2300 (b) 230 (c) 23
  38. 38.√90 to 1 decimal place? (a) 9.6 (b) 9.5 (c) 9.3 (d) 9.4
  39. 39.Best estimate of 4392 ÷ 59? (a) 7300 (b) 730 (c) 73
  40. 40.Best estimate of 738 ÷ 46? (a) 15 (b) 150 (c) 1500

Answer key

  1. 8.2
  2. 33
  3. 51
  4. 6.3
  5. 23
  6. 7.1
  7. 61
  8. 49
  9. 9.1
  10. 88
  11. 92
  12. 9.3
  13. 68
  14. 4.8
  15. 52
  16. 4.7
  17. 8.7
  18. 26
  19. 7.6
  20. 58
  21. 6.1
  22. 8.4
  23. 25
  24. 8.6
  25. 50
  26. 9.2
  27. 79
  28. 29
  29. 29
  30. 63
  31. 27
  32. 39
  33. 9.8
  34. 7.9
  35. 9.7
  36. 9.4
  37. 23
  38. 9.5
  39. 73
  40. 15

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