← Estimate divisions and square roots lesson New set →

Estimating Square Roots and Division Worksheet

Mental maths lesson 27: Estimate divisions and square roots · Set 481 · 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.√27 to 1 decimal place? (a) 5.2 (b) 5.1 (c) 5.3 (d) 5.0
  2. 2.√98 to 1 decimal place? (a) 9.9 (b) 9.8 (c) 10.0 (d) 9.7
  3. 3.Best estimate of 1520 ÷ 27? (a) 51 (b) 5100 (c) 510
  4. 4.√26 to 1 decimal place? (a) 5.1 (b) 4.9 (c) 4.8 (d) 5.0
  5. 5.Best estimate of 1102 ÷ 32? (a) 370 (b) 37 (c) 3700
  6. 6.√53 to 1 decimal place? (a) 7.1 (b) 7.2 (c) 7.0 (d) 7.3
  7. 7.√77 to 1 decimal place? (a) 8.9 (b) 8.8 (c) 8.7 (d) 9.0
  8. 8.√37 to 1 decimal place? (a) 6.1 (b) 6.3 (c) 6.4 (d) 6.2
  9. 9.Best estimate of 637 ÷ 51? (a) 130 (b) 1300 (c) 13
  10. 10.Best estimate of 4014 ÷ 54? (a) 8000 (b) 800 (c) 80
  11. 11.Best estimate of 5559 ÷ 82? (a) 690 (b) 6900 (c) 69
  12. 12.√94 to 1 decimal place? (a) 9.8 (b) 9.9 (c) 10.0 (d) 9.7
  13. 13.Best estimate of 2351 ÷ 38? (a) 59 (b) 5900 (c) 590
  14. 14.Best estimate of 3905 ÷ 53? (a) 78 (b) 780 (c) 7800
  15. 15.Best estimate of 1673 ÷ 34? (a) 5600 (b) 560 (c) 56
  16. 16.√45 to 1 decimal place? (a) 6.8 (b) 6.5 (c) 6.7 (d) 6.6
  17. 17.√86 to 1 decimal place? (a) 9.2 (b) 9.1 (c) 9.4 (d) 9.3
  18. 18.√69 to 1 decimal place? (a) 8.1 (b) 8.2 (c) 8.0 (d) 8.3
  19. 19.√65 to 1 decimal place? (a) 8.1 (b) 8.2 (c) 8.4 (d) 8.3
  20. 20.Best estimate of 4128 ÷ 53? (a) 8300 (b) 83 (c) 830
  21. 21.Best estimate of 906 ÷ 47? (a) 1800 (b) 180 (c) 18
  22. 22.Best estimate of 3752 ÷ 53? (a) 75 (b) 7500 (c) 750
  23. 23.Best estimate of 3639 ÷ 56? (a) 61 (b) 610 (c) 6100
  24. 24.Best estimate of 2307 ÷ 32? (a) 77 (b) 7700 (c) 770
  25. 25.√62 to 1 decimal place? (a) 8.2 (b) 8.0 (c) 7.9 (d) 8.1
  26. 26.√52 to 1 decimal place? (a) 7.2 (b) 7.3 (c) 7.5 (d) 7.4
  27. 27.Best estimate of 1620 ÷ 22? (a) 810 (b) 8100 (c) 81
  28. 28.Best estimate of 2189 ÷ 47? (a) 44 (b) 4400 (c) 440
  29. 29.Best estimate of 1229 ÷ 73? (a) 1800 (b) 180 (c) 18
  30. 30.Best estimate of 968 ÷ 44? (a) 240 (b) 24 (c) 2400
  31. 31.Best estimate of 1545 ÷ 37? (a) 3900 (b) 390 (c) 39
  32. 32.Best estimate of 3210 ÷ 66? (a) 4600 (b) 460 (c) 46
  33. 33.Best estimate of 1771 ÷ 48? (a) 350 (b) 3500 (c) 35
  34. 34.Best estimate of 2634 ÷ 42? (a) 66 (b) 6600 (c) 660
  35. 35.Best estimate of 3759 ÷ 52? (a) 7500 (b) 750 (c) 75
  36. 36.√71 to 1 decimal place? (a) 8.3 (b) 8.1 (c) 8.4 (d) 8.2
  37. 37.√74 to 1 decimal place? (a) 8.4 (b) 8.5 (c) 8.7 (d) 8.6
  38. 38.√48 to 1 decimal place? (a) 6.8 (b) 6.7 (c) 6.6 (d) 6.9
  39. 39.Best estimate of 777 ÷ 27? (a) 2600 (b) 26 (c) 260
  40. 40.Best estimate of 1990 ÷ 31? (a) 66 (b) 660 (c) 6600

Answer key

  1. 5.2
  2. 9.9
  3. 51
  4. 5.1
  5. 37
  6. 7.3
  7. 8.8
  8. 6.1
  9. 13
  10. 80
  11. 69
  12. 9.7
  13. 59
  14. 78
  15. 56
  16. 6.7
  17. 9.3
  18. 8.3
  19. 8.1
  20. 83
  21. 18
  22. 75
  23. 61
  24. 77
  25. 7.9
  26. 7.2
  27. 81
  28. 44
  29. 18
  30. 24
  31. 39
  32. 46
  33. 35
  34. 66
  35. 75
  36. 8.4
  37. 8.6
  38. 6.9
  39. 26
  40. 66

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