← Estimate divisions and square roots lesson New set →

Estimating Square Roots and Division Worksheet

Mental maths lesson 27: Estimate divisions and square roots · Set 342 · 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 5245 ÷ 76? (a) 660 (b) 6600 (c) 66
  2. 2.√56 to 1 decimal place? (a) 7.4 (b) 7.6 (c) 7.5 (d) 7.7
  3. 3.Best estimate of 2905 ÷ 54? (a) 580 (b) 5800 (c) 58
  4. 4.Best estimate of 3906 ÷ 56? (a) 65 (b) 6500 (c) 650
  5. 5.Best estimate of 4206 ÷ 83? (a) 530 (b) 5300 (c) 53
  6. 6.√62 to 1 decimal place? (a) 8.2 (b) 7.9 (c) 8.0 (d) 8.1
  7. 7.√45 to 1 decimal place? (a) 6.7 (b) 6.8 (c) 6.5 (d) 6.6
  8. 8.Best estimate of 2850 ÷ 39? (a) 7100 (b) 71 (c) 710
  9. 9.Best estimate of 7194 ÷ 82? (a) 90 (b) 9000 (c) 900
  10. 10.Best estimate of 3924 ÷ 54? (a) 78 (b) 780 (c) 7800
  11. 11.√79 to 1 decimal place? (a) 9.0 (b) 8.9 (c) 9.2 (d) 9.1
  12. 12.Best estimate of 5851 ÷ 66? (a) 8400 (b) 840 (c) 84
  13. 13.Best estimate of 3456 ÷ 47? (a) 69 (b) 690 (c) 6900
  14. 14.√92 to 1 decimal place? (a) 9.7 (b) 9.5 (c) 9.6 (d) 9.8
  15. 15.Best estimate of 1098 ÷ 29? (a) 370 (b) 37 (c) 3700
  16. 16.√38 to 1 decimal place? (a) 6.0 (b) 6.1 (c) 6.3 (d) 6.2
  17. 17.√96 to 1 decimal place? (a) 9.9 (b) 9.8 (c) 10.0 (d) 10.1
  18. 18.√98 to 1 decimal place? (a) 9.7 (b) 9.6 (c) 9.9 (d) 9.8
  19. 19.√74 to 1 decimal place? (a) 8.6 (b) 8.4 (c) 8.5 (d) 8.3
  20. 20.Best estimate of 2579 ÷ 48? (a) 5200 (b) 52 (c) 520
  21. 21.Best estimate of 667 ÷ 51? (a) 13 (b) 130 (c) 1300
  22. 22.Best estimate of 3498 ÷ 42? (a) 87 (b) 8700 (c) 870
  23. 23.√26 to 1 decimal place? (a) 5.0 (b) 5.1 (c) 4.9 (d) 4.8
  24. 24.√66 to 1 decimal place? (a) 8.3 (b) 8.1 (c) 8.2 (d) 8.0
  25. 25.Best estimate of 1542 ÷ 32? (a) 5100 (b) 51 (c) 510
  26. 26.Best estimate of 3985 ÷ 58? (a) 660 (b) 66 (c) 6600
  27. 27.Best estimate of 3008 ÷ 48? (a) 6000 (b) 600 (c) 60
  28. 28.√84 to 1 decimal place? (a) 9.1 (b) 9.0 (c) 9.2 (d) 9.3
  29. 29.√35 to 1 decimal place? (a) 5.9 (b) 5.8 (c) 5.6 (d) 5.7
  30. 30.√40 to 1 decimal place? (a) 6.5 (b) 6.6 (c) 6.3 (d) 6.4
  31. 31.Best estimate of 1295 ÷ 51? (a) 2600 (b) 260 (c) 26
  32. 32.√34 to 1 decimal place? (a) 5.8 (b) 6.0 (c) 5.9 (d) 5.7
  33. 33.√46 to 1 decimal place? (a) 6.8 (b) 6.5 (c) 6.7 (d) 6.6
  34. 34.Best estimate of 6310 ÷ 72? (a) 9000 (b) 900 (c) 90
  35. 35.Best estimate of 2349 ÷ 69? (a) 34 (b) 340 (c) 3400
  36. 36.Best estimate of 2131 ÷ 77? (a) 270 (b) 2700 (c) 27
  37. 37.√72 to 1 decimal place? (a) 8.2 (b) 8.5 (c) 8.4 (d) 8.3
  38. 38.Best estimate of 1428 ÷ 24? (a) 710 (b) 7100 (c) 71
  39. 39.√42 to 1 decimal place? (a) 6.7 (b) 6.8 (c) 6.5 (d) 6.6
  40. 40.√63 to 1 decimal place? (a) 7.9 (b) 8.0 (c) 7.8 (d) 8.1

Answer key

  1. 66
  2. 7.5
  3. 58
  4. 65
  5. 53
  6. 7.9
  7. 6.7
  8. 71
  9. 90
  10. 78
  11. 8.9
  12. 84
  13. 69
  14. 9.6
  15. 37
  16. 6.2
  17. 9.8
  18. 9.9
  19. 8.6
  20. 52
  21. 13
  22. 87
  23. 5.1
  24. 8.1
  25. 51
  26. 66
  27. 60
  28. 9.2
  29. 5.9
  30. 6.3
  31. 26
  32. 5.8
  33. 6.8
  34. 90
  35. 34
  36. 27
  37. 8.5
  38. 71
  39. 6.5
  40. 7.9

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