← Estimate divisions and square roots lesson New set →

Estimating Square Roots and Division Worksheet

Mental maths lesson 27: Estimate divisions and square roots · Set 14 · 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 451 ÷ 22? (a) 2300 (b) 23 (c) 230
  2. 2.√67 to 1 decimal place? (a) 8.0 (b) 8.2 (c) 8.1 (d) 7.9
  3. 3.Best estimate of 1204 ÷ 24? (a) 6000 (b) 60 (c) 600
  4. 4.Best estimate of 2619 ÷ 64? (a) 440 (b) 44 (c) 4400
  5. 5.√70 to 1 decimal place? (a) 8.3 (b) 8.1 (c) 8.2 (d) 8.4
  6. 6.√52 to 1 decimal place? (a) 7.4 (b) 7.3 (c) 7.2 (d) 7.5
  7. 7.√46 to 1 decimal place? (a) 6.9 (b) 6.8 (c) 6.7 (d) 6.6
  8. 8.√87 to 1 decimal place? (a) 9.1 (b) 9.3 (c) 9.2 (d) 9.0
  9. 9.Best estimate of 2172 ÷ 38? (a) 5400 (b) 540 (c) 54
  10. 10.√71 to 1 decimal place? (a) 8.4 (b) 8.5 (c) 8.2 (d) 8.3
  11. 11.√43 to 1 decimal place? (a) 6.8 (b) 6.7 (c) 6.6 (d) 6.9
  12. 12.Best estimate of 7773 ÷ 88? (a) 860 (b) 8600 (c) 86
  13. 13.√26 to 1 decimal place? (a) 5.2 (b) 4.9 (c) 5.1 (d) 5.0
  14. 14.Best estimate of 1921 ÷ 27? (a) 6400 (b) 64 (c) 640
  15. 15.Best estimate of 3123 ÷ 53? (a) 620 (b) 6200 (c) 62
  16. 16.Best estimate of 5054 ÷ 83? (a) 630 (b) 6300 (c) 63
  17. 17.√45 to 1 decimal place? (a) 6.7 (b) 6.8 (c) 6.6 (d) 6.9
  18. 18.√74 to 1 decimal place? (a) 8.5 (b) 8.6 (c) 8.7 (d) 8.4
  19. 19.Best estimate of 2963 ÷ 76? (a) 37 (b) 370 (c) 3700
  20. 20.√30 to 1 decimal place? (a) 5.4 (b) 5.6 (c) 5.5 (d) 5.3
  21. 21.√96 to 1 decimal place? (a) 9.6 (b) 9.8 (c) 9.7 (d) 9.9
  22. 22.√37 to 1 decimal place? (a) 6.0 (b) 5.9 (c) 6.1 (d) 5.8
  23. 23.Best estimate of 5268 ÷ 72? (a) 7500 (b) 75 (c) 750
  24. 24.Best estimate of 1221 ÷ 41? (a) 3100 (b) 310 (c) 31
  25. 25.Best estimate of 514 ÷ 27? (a) 1700 (b) 17 (c) 170
  26. 26.Best estimate of 1451 ÷ 36? (a) 3600 (b) 360 (c) 36
  27. 27.Best estimate of 1770 ÷ 68? (a) 250 (b) 2500 (c) 25
  28. 28.√63 to 1 decimal place? (a) 7.9 (b) 8.1 (c) 8.0 (d) 8.2
  29. 29.Best estimate of 7413 ÷ 86? (a) 8200 (b) 82 (c) 820
  30. 30.Best estimate of 3405 ÷ 48? (a) 6800 (b) 680 (c) 68
  31. 31.Best estimate of 1809 ÷ 79? (a) 230 (b) 23 (c) 2300
  32. 32.Best estimate of 1946 ÷ 36? (a) 4900 (b) 49 (c) 490
  33. 33.Best estimate of 2122 ÷ 54? (a) 420 (b) 4200 (c) 42
  34. 34.Best estimate of 5699 ÷ 72? (a) 810 (b) 81 (c) 8100
  35. 35.Best estimate of 5612 ÷ 83? (a) 700 (b) 7000 (c) 70
  36. 36.Best estimate of 1653 ÷ 89? (a) 180 (b) 1800 (c) 18
  37. 37.√42 to 1 decimal place? (a) 6.6 (b) 6.8 (c) 6.7 (d) 6.5
  38. 38.Best estimate of 3249 ÷ 72? (a) 46 (b) 4600 (c) 460
  39. 39.Best estimate of 1500 ÷ 34? (a) 5000 (b) 500 (c) 50
  40. 40.Best estimate of 1441 ÷ 32? (a) 4800 (b) 48 (c) 480

Answer key

  1. 23
  2. 8.2
  3. 60
  4. 44
  5. 8.4
  6. 7.2
  7. 6.8
  8. 9.3
  9. 54
  10. 8.4
  11. 6.6
  12. 86
  13. 5.1
  14. 64
  15. 62
  16. 63
  17. 6.7
  18. 8.6
  19. 37
  20. 5.5
  21. 9.8
  22. 6.1
  23. 75
  24. 31
  25. 17
  26. 36
  27. 25
  28. 7.9
  29. 82
  30. 68
  31. 23
  32. 49
  33. 42
  34. 81
  35. 70
  36. 18
  37. 6.5
  38. 46
  39. 50
  40. 48

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