← Estimate divisions and square roots lesson New set →

Estimating Square Roots and Division Worksheet

Mental maths lesson 27: Estimate divisions and square roots · Set 292 · 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.√50 to 1 decimal place? (a) 7.2 (b) 6.9 (c) 7.1 (d) 7.0
  2. 2.Best estimate of 560 ÷ 39? (a) 140 (b) 14 (c) 1400
  3. 3.Best estimate of 1776 ÷ 69? (a) 25 (b) 2500 (c) 250
  4. 4.√26 to 1 decimal place? (a) 5.2 (b) 5.0 (c) 5.1 (d) 5.3
  5. 5.Best estimate of 1400 ÷ 32? (a) 470 (b) 4700 (c) 47
  6. 6.Best estimate of 5666 ÷ 63? (a) 9400 (b) 94 (c) 940
  7. 7.√84 to 1 decimal place? (a) 9.1 (b) 9.2 (c) 9.0 (d) 9.3
  8. 8.Best estimate of 2143 ÷ 57? (a) 3600 (b) 360 (c) 36
  9. 9.Best estimate of 4598 ÷ 76? (a) 5700 (b) 570 (c) 57
  10. 10.√72 to 1 decimal place? (a) 8.5 (b) 8.4 (c) 8.6 (d) 8.3
  11. 11.√80 to 1 decimal place? (a) 9.2 (b) 9.0 (c) 8.9 (d) 9.1
  12. 12.√29 to 1 decimal place? (a) 5.7 (b) 5.6 (c) 5.5 (d) 5.4
  13. 13.√52 to 1 decimal place? (a) 7.2 (b) 7.5 (c) 7.4 (d) 7.3
  14. 14.√41 to 1 decimal place? (a) 6.4 (b) 6.2 (c) 6.1 (d) 6.3
  15. 15.Best estimate of 1013 ÷ 42? (a) 25 (b) 250 (c) 2500
  16. 16.√58 to 1 decimal place? (a) 7.4 (b) 7.6 (c) 7.3 (d) 7.5
  17. 17.Best estimate of 928 ÷ 44? (a) 23 (b) 2300 (c) 230
  18. 18.√69 to 1 decimal place? (a) 8.2 (b) 8.0 (c) 8.1 (d) 8.3
  19. 19.√96 to 1 decimal place? (a) 9.8 (b) 10.0 (c) 9.9 (d) 9.7
  20. 20.√46 to 1 decimal place? (a) 7.1 (b) 6.9 (c) 7.0 (d) 6.8
  21. 21.√47 to 1 decimal place? (a) 7.0 (b) 6.8 (c) 6.7 (d) 6.9
  22. 22.√63 to 1 decimal place? (a) 8.0 (b) 7.9 (c) 7.7 (d) 7.8
  23. 23.Best estimate of 3219 ÷ 62? (a) 540 (b) 5400 (c) 54
  24. 24.Best estimate of 5515 ÷ 67? (a) 790 (b) 7900 (c) 79
  25. 25.√37 to 1 decimal place? (a) 6.0 (b) 6.1 (c) 6.2 (d) 5.9
  26. 26.√83 to 1 decimal place? (a) 9.2 (b) 9.3 (c) 9.0 (d) 9.1
  27. 27.Best estimate of 878 ÷ 32? (a) 29 (b) 2900 (c) 290
  28. 28.Best estimate of 806 ÷ 22? (a) 40 (b) 4000 (c) 400
  29. 29.√55 to 1 decimal place? (a) 7.4 (b) 7.6 (c) 7.5 (d) 7.7
  30. 30.Best estimate of 2381 ÷ 31? (a) 7900 (b) 790 (c) 79
  31. 31.√42 to 1 decimal place? (a) 6.5 (b) 6.3 (c) 6.4 (d) 6.6
  32. 32.√65 to 1 decimal place? (a) 7.9 (b) 8.1 (c) 8.2 (d) 8.0
  33. 33.Best estimate of 4654 ÷ 57? (a) 7800 (b) 78 (c) 780
  34. 34.√30 to 1 decimal place? (a) 5.3 (b) 5.5 (c) 5.4 (d) 5.2
  35. 35.√34 to 1 decimal place? (a) 5.8 (b) 5.9 (c) 5.7 (d) 5.6
  36. 36.Best estimate of 7547 ÷ 82? (a) 9400 (b) 940 (c) 94
  37. 37.√22 to 1 decimal place? (a) 4.6 (b) 4.4 (c) 4.7 (d) 4.5
  38. 38.Best estimate of 2003 ÷ 58? (a) 33 (b) 330 (c) 3300
  39. 39.Best estimate of 1431 ÷ 62? (a) 240 (b) 2400 (c) 24
  40. 40.Best estimate of 1908 ÷ 73? (a) 270 (b) 2700 (c) 27

Answer key

  1. 7.1
  2. 14
  3. 25
  4. 5.1
  5. 47
  6. 94
  7. 9.2
  8. 36
  9. 57
  10. 8.5
  11. 8.9
  12. 5.4
  13. 7.2
  14. 6.4
  15. 25
  16. 7.6
  17. 23
  18. 8.3
  19. 9.8
  20. 6.8
  21. 6.9
  22. 7.9
  23. 54
  24. 79
  25. 6.1
  26. 9.1
  27. 29
  28. 40
  29. 7.4
  30. 79
  31. 6.5
  32. 8.1
  33. 78
  34. 5.5
  35. 5.8
  36. 94
  37. 4.7
  38. 33
  39. 24
  40. 27

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