← Estimate divisions and square roots lesson New set →

Estimating Square Roots and Division Worksheet

Mental maths lesson 27: Estimate divisions and square roots · Set 30 · 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 3434 ÷ 81? (a) 43 (b) 430 (c) 4300
  2. 2.√86 to 1 decimal place? (a) 9.1 (b) 9.4 (c) 9.2 (d) 9.3
  3. 3.Best estimate of 3580 ÷ 38? (a) 9000 (b) 900 (c) 90
  4. 4.Best estimate of 5208 ÷ 72? (a) 740 (b) 7400 (c) 74
  5. 5.Best estimate of 714 ÷ 26? (a) 24 (b) 240 (c) 2400
  6. 6.√55 to 1 decimal place? (a) 7.4 (b) 7.5 (c) 7.7 (d) 7.6
  7. 7.√20 to 1 decimal place? (a) 4.3 (b) 4.4 (c) 4.5 (d) 4.2
  8. 8.√74 to 1 decimal place? (a) 8.7 (b) 8.8 (c) 8.9 (d) 8.6
  9. 9.√37 to 1 decimal place? (a) 6.3 (b) 6.2 (c) 6.1 (d) 6.4
  10. 10.Best estimate of 624 ÷ 24? (a) 310 (b) 31 (c) 3100
  11. 11.Best estimate of 4087 ÷ 56? (a) 6800 (b) 68 (c) 680
  12. 12.Best estimate of 4638 ÷ 73? (a) 66 (b) 6600 (c) 660
  13. 13.√70 to 1 decimal place? (a) 8.3 (b) 8.4 (c) 8.1 (d) 8.2
  14. 14.√22 to 1 decimal place? (a) 4.6 (b) 4.7 (c) 4.5 (d) 4.4
  15. 15.√98 to 1 decimal place? (a) 9.9 (b) 9.6 (c) 9.7 (d) 9.8
  16. 16.√94 to 1 decimal place? (a) 9.6 (b) 9.5 (c) 9.8 (d) 9.7
  17. 17.Best estimate of 1543 ÷ 82? (a) 1900 (b) 19 (c) 190
  18. 18.Best estimate of 3140 ÷ 73? (a) 450 (b) 4500 (c) 45
  19. 19.Best estimate of 5557 ÷ 86? (a) 6200 (b) 620 (c) 62
  20. 20.Best estimate of 3680 ÷ 81? (a) 460 (b) 4600 (c) 46
  21. 21.Best estimate of 7093 ÷ 74? (a) 101 (b) 10100 (c) 1010
  22. 22.√85 to 1 decimal place? (a) 9.0 (b) 9.1 (c) 9.2 (d) 9.3
  23. 23.Best estimate of 1438 ÷ 34? (a) 48 (b) 480 (c) 4800
  24. 24.Best estimate of 1941 ÷ 58? (a) 320 (b) 3200 (c) 32
  25. 25.√89 to 1 decimal place? (a) 9.4 (b) 9.3 (c) 9.2 (d) 9.5
  26. 26.√65 to 1 decimal place? (a) 7.9 (b) 8.1 (c) 7.8 (d) 8.0
  27. 27.Best estimate of 2290 ÷ 29? (a) 7600 (b) 76 (c) 760
  28. 28.√41 to 1 decimal place? (a) 6.3 (b) 6.6 (c) 6.4 (d) 6.5
  29. 29.Best estimate of 1576 ÷ 86? (a) 1800 (b) 18 (c) 180
  30. 30.Best estimate of 2847 ÷ 66? (a) 4100 (b) 410 (c) 41
  31. 31.√48 to 1 decimal place? (a) 6.9 (b) 7.0 (c) 6.7 (d) 6.8
  32. 32.Best estimate of 2882 ÷ 57? (a) 48 (b) 4800 (c) 480
  33. 33.Best estimate of 2880 ÷ 32? (a) 9600 (b) 96 (c) 960
  34. 34.Best estimate of 1268 ÷ 37? (a) 32 (b) 320 (c) 3200
  35. 35.√84 to 1 decimal place? (a) 9.2 (b) 9.1 (c) 9.0 (d) 9.3
  36. 36.Best estimate of 1300 ÷ 41? (a) 3300 (b) 33 (c) 330
  37. 37.Best estimate of 3061 ÷ 36? (a) 7700 (b) 77 (c) 770
  38. 38.√31 to 1 decimal place? (a) 5.5 (b) 5.6 (c) 5.4 (d) 5.7
  39. 39.√88 to 1 decimal place? (a) 9.5 (b) 9.4 (c) 9.6 (d) 9.7
  40. 40.Best estimate of 1813 ÷ 44? (a) 450 (b) 4500 (c) 45

Answer key

  1. 43
  2. 9.3
  3. 90
  4. 74
  5. 24
  6. 7.4
  7. 4.5
  8. 8.6
  9. 6.1
  10. 31
  11. 68
  12. 66
  13. 8.4
  14. 4.7
  15. 9.9
  16. 9.7
  17. 19
  18. 45
  19. 62
  20. 46
  21. 101
  22. 9.2
  23. 48
  24. 32
  25. 9.4
  26. 8.1
  27. 76
  28. 6.4
  29. 18
  30. 41
  31. 6.9
  32. 48
  33. 96
  34. 32
  35. 9.2
  36. 33
  37. 77
  38. 5.6
  39. 9.4
  40. 45

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