← Estimate divisions and square roots lesson New set →

Estimating Square Roots and Division Worksheet

Mental maths lesson 27: Estimate divisions and square roots · Set 537 · 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.√56 to 1 decimal place? (a) 7.7 (b) 7.8 (c) 7.6 (d) 7.5
  2. 2.Best estimate of 1336 ÷ 73? (a) 190 (b) 1900 (c) 19
  3. 3.Best estimate of 1542 ÷ 37? (a) 3900 (b) 390 (c) 39
  4. 4.√38 to 1 decimal place? (a) 6.1 (b) 6.2 (c) 6.4 (d) 6.3
  5. 5.√50 to 1 decimal place? (a) 7.1 (b) 7.2 (c) 7.0 (d) 6.9
  6. 6.√30 to 1 decimal place? (a) 5.5 (b) 5.8 (c) 5.6 (d) 5.7
  7. 7.Best estimate of 1177 ÷ 63? (a) 20 (b) 2000 (c) 200
  8. 8.√28 to 1 decimal place? (a) 5.3 (b) 5.4 (c) 5.2 (d) 5.5
  9. 9.Best estimate of 836 ÷ 33? (a) 28 (b) 280 (c) 2800
  10. 10.√84 to 1 decimal place? (a) 9.1 (b) 9.2 (c) 8.9 (d) 9.0
  11. 11.Best estimate of 3839 ÷ 59? (a) 6400 (b) 640 (c) 64
  12. 12.√44 to 1 decimal place? (a) 6.8 (b) 6.6 (c) 6.9 (d) 6.7
  13. 13.√65 to 1 decimal place? (a) 8.1 (b) 7.8 (c) 8.0 (d) 7.9
  14. 14.√79 to 1 decimal place? (a) 9.2 (b) 9.1 (c) 8.9 (d) 9.0
  15. 15.√41 to 1 decimal place? (a) 6.2 (b) 6.3 (c) 6.5 (d) 6.4
  16. 16.√42 to 1 decimal place? (a) 6.4 (b) 6.5 (c) 6.3 (d) 6.6
  17. 17.Best estimate of 4368 ÷ 56? (a) 7300 (b) 730 (c) 73
  18. 18.Best estimate of 5833 ÷ 72? (a) 8300 (b) 83 (c) 830
  19. 19.Best estimate of 2217 ÷ 86? (a) 25 (b) 2500 (c) 250
  20. 20.√26 to 1 decimal place? (a) 5.1 (b) 5.0 (c) 5.2 (d) 4.9
  21. 21.√92 to 1 decimal place? (a) 9.4 (b) 9.6 (c) 9.7 (d) 9.5
  22. 22.√75 to 1 decimal place? (a) 8.7 (b) 8.9 (c) 8.8 (d) 9.0
  23. 23.Best estimate of 5323 ÷ 86? (a) 5900 (b) 59 (c) 590
  24. 24.Best estimate of 1820 ÷ 23? (a) 91 (b) 910 (c) 9100
  25. 25.Best estimate of 6434 ÷ 78? (a) 800 (b) 80 (c) 8000
  26. 26.√90 to 1 decimal place? (a) 9.6 (b) 9.8 (c) 9.7 (d) 9.5
  27. 27.√74 to 1 decimal place? (a) 8.7 (b) 8.6 (c) 8.8 (d) 8.9
  28. 28.√58 to 1 decimal place? (a) 7.7 (b) 7.6 (c) 7.5 (d) 7.4
  29. 29.Best estimate of 2117 ÷ 34? (a) 71 (b) 710 (c) 7100
  30. 30.Best estimate of 2527 ÷ 44? (a) 6300 (b) 63 (c) 630
  31. 31.√69 to 1 decimal place? (a) 8.3 (b) 8.4 (c) 8.5 (d) 8.2
  32. 32.Best estimate of 1832 ÷ 86? (a) 200 (b) 2000 (c) 20
  33. 33.Best estimate of 3751 ÷ 43? (a) 9400 (b) 94 (c) 940
  34. 34.√45 to 1 decimal place? (a) 6.6 (b) 6.5 (c) 6.8 (d) 6.7
  35. 35.√63 to 1 decimal place? (a) 7.8 (b) 7.9 (c) 8.0 (d) 8.1
  36. 36.Best estimate of 2086 ÷ 82? (a) 26 (b) 2600 (c) 260
  37. 37.Best estimate of 1718 ÷ 27? (a) 5700 (b) 570 (c) 57
  38. 38.Best estimate of 434 ÷ 21? (a) 220 (b) 2200 (c) 22
  39. 39.Best estimate of 1745 ÷ 72? (a) 250 (b) 25 (c) 2500
  40. 40.√34 to 1 decimal place? (a) 5.8 (b) 5.9 (c) 6.0 (d) 5.7

Answer key

  1. 7.5
  2. 19
  3. 39
  4. 6.2
  5. 7.1
  6. 5.5
  7. 20
  8. 5.3
  9. 28
  10. 9.2
  11. 64
  12. 6.6
  13. 8.1
  14. 8.9
  15. 6.4
  16. 6.5
  17. 73
  18. 83
  19. 25
  20. 5.1
  21. 9.6
  22. 8.7
  23. 59
  24. 91
  25. 80
  26. 9.5
  27. 8.6
  28. 7.6
  29. 71
  30. 63
  31. 8.3
  32. 20
  33. 94
  34. 6.7
  35. 7.9
  36. 26
  37. 57
  38. 22
  39. 25
  40. 5.8

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