← Estimate divisions and square roots lesson New set →

Estimating Square Roots and Division Worksheet

Mental maths lesson 27: Estimate divisions and square roots · Set 530 · 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 2647 ÷ 32? (a) 880 (b) 88 (c) 8800
  2. 2.Best estimate of 1573 ÷ 73? (a) 220 (b) 22 (c) 2200
  3. 3.Best estimate of 1326 ÷ 77? (a) 1700 (b) 170 (c) 17
  4. 4.Best estimate of 1716 ÷ 89? (a) 190 (b) 1900 (c) 19
  5. 5.√37 to 1 decimal place? (a) 6.2 (b) 6.0 (c) 6.3 (d) 6.1
  6. 6.√71 to 1 decimal place? (a) 8.4 (b) 8.5 (c) 8.3 (d) 8.6
  7. 7.√65 to 1 decimal place? (a) 8.3 (b) 8.4 (c) 8.1 (d) 8.2
  8. 8.√76 to 1 decimal place? (a) 8.7 (b) 8.4 (c) 8.6 (d) 8.5
  9. 9.Best estimate of 354 ÷ 28? (a) 1200 (b) 120 (c) 12
  10. 10.√44 to 1 decimal place? (a) 6.8 (b) 6.5 (c) 6.7 (d) 6.6
  11. 11.√42 to 1 decimal place? (a) 6.7 (b) 6.6 (c) 6.5 (d) 6.4
  12. 12.√29 to 1 decimal place? (a) 5.4 (b) 5.5 (c) 5.3 (d) 5.2
  13. 13.√22 to 1 decimal place? (a) 4.8 (b) 5.0 (c) 4.9 (d) 4.7
  14. 14.√96 to 1 decimal place? (a) 9.9 (b) 9.8 (c) 10.1 (d) 10.0
  15. 15.Best estimate of 877 ÷ 51? (a) 18 (b) 180 (c) 1800
  16. 16.Best estimate of 3963 ÷ 61? (a) 6600 (b) 66 (c) 660
  17. 17.√82 to 1 decimal place? (a) 9.1 (b) 9.0 (c) 9.2 (d) 9.3
  18. 18.Best estimate of 1438 ÷ 64? (a) 24 (b) 2400 (c) 240
  19. 19.√34 to 1 decimal place? (a) 5.9 (b) 6.1 (c) 5.8 (d) 6.0
  20. 20.Best estimate of 871 ÷ 28? (a) 2900 (b) 29 (c) 290
  21. 21.Best estimate of 3631 ÷ 53? (a) 73 (b) 7300 (c) 730
  22. 22.Best estimate of 863 ÷ 66? (a) 120 (b) 12 (c) 1200
  23. 23.Best estimate of 2855 ÷ 32? (a) 9500 (b) 950 (c) 95
  24. 24.Best estimate of 3056 ÷ 58? (a) 5100 (b) 51 (c) 510
  25. 25.√70 to 1 decimal place? (a) 8.5 (b) 8.6 (c) 8.7 (d) 8.4
  26. 26.√38 to 1 decimal place? (a) 6.1 (b) 6.3 (c) 6.4 (d) 6.2
  27. 27.Best estimate of 1688 ÷ 57? (a) 28 (b) 2800 (c) 280
  28. 28.Best estimate of 2463 ÷ 76? (a) 3100 (b) 31 (c) 310
  29. 29.Best estimate of 4088 ÷ 56? (a) 680 (b) 6800 (c) 68
  30. 30.Best estimate of 4347 ÷ 64? (a) 72 (b) 7200 (c) 720
  31. 31.√26 to 1 decimal place? (a) 5.2 (b) 5.1 (c) 5.3 (d) 5.0
  32. 32.Best estimate of 2780 ÷ 41? (a) 700 (b) 70 (c) 7000
  33. 33.Best estimate of 3112 ÷ 53? (a) 6200 (b) 62 (c) 620
  34. 34.Best estimate of 3368 ÷ 36? (a) 840 (b) 84 (c) 8400
  35. 35.Best estimate of 2504 ÷ 44? (a) 63 (b) 6300 (c) 630
  36. 36.Best estimate of 1237 ÷ 68? (a) 18 (b) 1800 (c) 180
  37. 37.√67 to 1 decimal place? (a) 8.1 (b) 8.2 (c) 8.0 (d) 7.9
  38. 38.Best estimate of 4260 ÷ 76? (a) 53 (b) 5300 (c) 530
  39. 39.√58 to 1 decimal place? (a) 7.6 (b) 7.7 (c) 7.9 (d) 7.8
  40. 40.Best estimate of 2510 ÷ 37? (a) 6300 (b) 63 (c) 630

Answer key

  1. 88
  2. 22
  3. 17
  4. 19
  5. 6.1
  6. 8.4
  7. 8.1
  8. 8.7
  9. 12
  10. 6.6
  11. 6.5
  12. 5.4
  13. 4.7
  14. 9.8
  15. 18
  16. 66
  17. 9.1
  18. 24
  19. 5.8
  20. 29
  21. 73
  22. 12
  23. 95
  24. 51
  25. 8.4
  26. 6.2
  27. 28
  28. 31
  29. 68
  30. 72
  31. 5.1
  32. 70
  33. 62
  34. 84
  35. 63
  36. 18
  37. 8.2
  38. 53
  39. 7.6
  40. 63

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