← Estimate divisions and square roots lesson New set →

Estimating Square Roots and Division Worksheet

Mental maths lesson 27: Estimate divisions and square roots · Set 418 · 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.√75 to 1 decimal place? (a) 8.9 (b) 8.8 (c) 8.6 (d) 8.7
  2. 2.√69 to 1 decimal place? (a) 8.4 (b) 8.3 (c) 8.2 (d) 8.5
  3. 3.√43 to 1 decimal place? (a) 6.5 (b) 6.4 (c) 6.6 (d) 6.7
  4. 4.Best estimate of 1145 ÷ 41? (a) 290 (b) 29 (c) 2900
  5. 5.Best estimate of 3563 ÷ 87? (a) 400 (b) 40 (c) 4000
  6. 6.√58 to 1 decimal place? (a) 7.6 (b) 7.7 (c) 7.5 (d) 7.4
  7. 7.Best estimate of 595 ÷ 32? (a) 20 (b) 200 (c) 2000
  8. 8.Best estimate of 5402 ÷ 87? (a) 60 (b) 6000 (c) 600
  9. 9.Best estimate of 1032 ÷ 22? (a) 52 (b) 520 (c) 5200
  10. 10.Best estimate of 3198 ÷ 52? (a) 6400 (b) 640 (c) 64
  11. 11.Best estimate of 4163 ÷ 78? (a) 52 (b) 520 (c) 5200
  12. 12.Best estimate of 2497 ÷ 66? (a) 3600 (b) 36 (c) 360
  13. 13.Best estimate of 3441 ÷ 83? (a) 4300 (b) 43 (c) 430
  14. 14.Best estimate of 938 ÷ 48? (a) 19 (b) 190 (c) 1900
  15. 15.√92 to 1 decimal place? (a) 9.8 (b) 9.6 (c) 9.5 (d) 9.7
  16. 16.Best estimate of 1718 ÷ 23? (a) 860 (b) 8600 (c) 86
  17. 17.Best estimate of 1601 ÷ 57? (a) 2700 (b) 270 (c) 27
  18. 18.Best estimate of 2697 ÷ 72? (a) 3900 (b) 39 (c) 390
  19. 19.Best estimate of 6693 ÷ 86? (a) 740 (b) 74 (c) 7400
  20. 20.√29 to 1 decimal place? (a) 5.6 (b) 5.4 (c) 5.7 (d) 5.5
  21. 21.Best estimate of 2924 ÷ 49? (a) 58 (b) 5800 (c) 580
  22. 22.Best estimate of 1311 ÷ 29? (a) 4400 (b) 440 (c) 44
  23. 23.Best estimate of 4166 ÷ 56? (a) 69 (b) 6900 (c) 690
  24. 24.√40 to 1 decimal place? (a) 6.3 (b) 6.4 (c) 6.1 (d) 6.2
  25. 25.Best estimate of 3784 ÷ 68? (a) 54 (b) 5400 (c) 540
  26. 26.√71 to 1 decimal place? (a) 8.4 (b) 8.3 (c) 8.2 (d) 8.1
  27. 27.Best estimate of 1493 ÷ 32? (a) 50 (b) 500 (c) 5000
  28. 28.√34 to 1 decimal place? (a) 5.9 (b) 6.1 (c) 6.0 (d) 5.8
  29. 29.Best estimate of 934 ÷ 26? (a) 310 (b) 31 (c) 3100
  30. 30.Best estimate of 6273 ÷ 74? (a) 90 (b) 900 (c) 9000
  31. 31.Best estimate of 752 ÷ 29? (a) 2500 (b) 250 (c) 25
  32. 32.Best estimate of 4700 ÷ 81? (a) 5900 (b) 59 (c) 590
  33. 33.√28 to 1 decimal place? (a) 5.4 (b) 5.6 (c) 5.5 (d) 5.3
  34. 34.√98 to 1 decimal place? (a) 9.8 (b) 10.1 (c) 10.0 (d) 9.9
  35. 35.Best estimate of 1160 ÷ 37? (a) 2900 (b) 290 (c) 29
  36. 36.√37 to 1 decimal place? (a) 5.8 (b) 6.1 (c) 5.9 (d) 6.0
  37. 37.√51 to 1 decimal place? (a) 6.8 (b) 7.1 (c) 6.9 (d) 7.0
  38. 38.Best estimate of 1664 ÷ 66? (a) 240 (b) 2400 (c) 24
  39. 39.Best estimate of 5703 ÷ 82? (a) 7100 (b) 71 (c) 710
  40. 40.√87 to 1 decimal place? (a) 9.5 (b) 9.3 (c) 9.6 (d) 9.4

Answer key

  1. 8.7
  2. 8.3
  3. 6.6
  4. 29
  5. 40
  6. 7.6
  7. 20
  8. 60
  9. 52
  10. 64
  11. 52
  12. 36
  13. 43
  14. 19
  15. 9.6
  16. 86
  17. 27
  18. 39
  19. 74
  20. 5.4
  21. 58
  22. 44
  23. 69
  24. 6.3
  25. 54
  26. 8.4
  27. 50
  28. 5.8
  29. 31
  30. 90
  31. 25
  32. 59
  33. 5.3
  34. 9.9
  35. 29
  36. 6.1
  37. 7.1
  38. 24
  39. 71
  40. 9.3

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