← Estimate divisions and square roots lesson New set →

Estimating Square Roots and Division Worksheet

Mental maths lesson 27: Estimate divisions and square roots · Set 722 · 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 920 ÷ 56? (a) 150 (b) 15 (c) 1500
  2. 2.√43 to 1 decimal place? (a) 6.9 (b) 6.6 (c) 6.8 (d) 6.7
  3. 3.Best estimate of 4020 ÷ 56? (a) 670 (b) 67 (c) 6700
  4. 4.√77 to 1 decimal place? (a) 8.8 (b) 9.0 (c) 8.7 (d) 8.9
  5. 5.Best estimate of 5048 ÷ 86? (a) 560 (b) 5600 (c) 56
  6. 6.Best estimate of 6032 ÷ 64? (a) 10100 (b) 1010 (c) 101
  7. 7.Best estimate of 1565 ÷ 57? (a) 26 (b) 2600 (c) 260
  8. 8.Best estimate of 872 ÷ 31? (a) 2900 (b) 29 (c) 290
  9. 9.√88 to 1 decimal place? (a) 9.3 (b) 9.5 (c) 9.2 (d) 9.4
  10. 10.Best estimate of 4732 ÷ 52? (a) 950 (b) 9500 (c) 95
  11. 11.√65 to 1 decimal place? (a) 8.1 (b) 8.0 (c) 7.9 (d) 8.2
  12. 12.√58 to 1 decimal place? (a) 7.9 (b) 7.8 (c) 7.7 (d) 7.6
  13. 13.Best estimate of 1433 ÷ 76? (a) 1800 (b) 18 (c) 180
  14. 14.√75 to 1 decimal place? (a) 8.9 (b) 8.8 (c) 8.7 (d) 9.0
  15. 15.√53 to 1 decimal place? (a) 7.3 (b) 7.5 (c) 7.6 (d) 7.4
  16. 16.Best estimate of 2570 ÷ 54? (a) 51 (b) 510 (c) 5100
  17. 17.√31 to 1 decimal place? (a) 5.6 (b) 5.7 (c) 5.9 (d) 5.8
  18. 18.Best estimate of 700 ÷ 26? (a) 230 (b) 23 (c) 2300
  19. 19.√92 to 1 decimal place? (a) 9.4 (b) 9.5 (c) 9.6 (d) 9.3
  20. 20.Best estimate of 1322 ÷ 32? (a) 440 (b) 4400 (c) 44
  21. 21.√28 to 1 decimal place? (a) 5.0 (b) 5.3 (c) 5.1 (d) 5.2
  22. 22.√40 to 1 decimal place? (a) 6.2 (b) 6.1 (c) 6.3 (d) 6.0
  23. 23.Best estimate of 1328 ÷ 36? (a) 33 (b) 3300 (c) 330
  24. 24.Best estimate of 1805 ÷ 21? (a) 9000 (b) 90 (c) 900
  25. 25.√32 to 1 decimal place? (a) 5.7 (b) 5.6 (c) 5.5 (d) 5.8
  26. 26.√38 to 1 decimal place? (a) 5.9 (b) 6.0 (c) 6.1 (d) 6.2
  27. 27.√74 to 1 decimal place? (a) 8.6 (b) 8.5 (c) 8.7 (d) 8.8
  28. 28.Best estimate of 2292 ÷ 41? (a) 570 (b) 5700 (c) 57
  29. 29.√30 to 1 decimal place? (a) 5.5 (b) 5.3 (c) 5.4 (d) 5.2
  30. 30.Best estimate of 875 ÷ 62? (a) 15 (b) 150 (c) 1500
  31. 31.Best estimate of 1377 ÷ 49? (a) 280 (b) 28 (c) 2800
  32. 32.√89 to 1 decimal place? (a) 9.4 (b) 9.5 (c) 9.2 (d) 9.3
  33. 33.Best estimate of 2605 ÷ 28? (a) 87 (b) 870 (c) 8700
  34. 34.√22 to 1 decimal place? (a) 4.9 (b) 4.6 (c) 4.7 (d) 4.8
  35. 35.Best estimate of 1882 ÷ 33? (a) 6300 (b) 630 (c) 63
  36. 36.√82 to 1 decimal place? (a) 8.8 (b) 9.1 (c) 8.9 (d) 9.0
  37. 37.√69 to 1 decimal place? (a) 8.4 (b) 8.2 (c) 8.5 (d) 8.3
  38. 38.Best estimate of 1923 ÷ 22? (a) 960 (b) 9600 (c) 96
  39. 39.Best estimate of 1172 ÷ 58? (a) 2000 (b) 200 (c) 20
  40. 40.√34 to 1 decimal place? (a) 6.1 (b) 5.8 (c) 5.9 (d) 6.0

Answer key

  1. 15
  2. 6.6
  3. 67
  4. 8.8
  5. 56
  6. 101
  7. 26
  8. 29
  9. 9.4
  10. 95
  11. 8.1
  12. 7.6
  13. 18
  14. 8.7
  15. 7.3
  16. 51
  17. 5.6
  18. 23
  19. 9.6
  20. 44
  21. 5.3
  22. 6.3
  23. 33
  24. 90
  25. 5.7
  26. 6.2
  27. 8.6
  28. 57
  29. 5.5
  30. 15
  31. 28
  32. 9.4
  33. 87
  34. 4.7
  35. 63
  36. 9.1
  37. 8.3
  38. 96
  39. 20
  40. 5.8

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