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Estimating Square Roots and Division Worksheet

Mental maths lesson 27: Estimate divisions and square roots · Set 624 · 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 3156 ÷ 38? (a) 7900 (b) 79 (c) 790
  2. 2.Best estimate of 4672 ÷ 76? (a) 5800 (b) 58 (c) 580
  3. 3.Best estimate of 1421 ÷ 22? (a) 71 (b) 7100 (c) 710
  4. 4.√51 to 1 decimal place? (a) 7.2 (b) 7.1 (c) 7.0 (d) 6.9
  5. 5.√26 to 1 decimal place? (a) 5.2 (b) 5.0 (c) 5.3 (d) 5.1
  6. 6.√58 to 1 decimal place? (a) 7.8 (b) 7.6 (c) 7.7 (d) 7.5
  7. 7.Best estimate of 1742 ÷ 43? (a) 440 (b) 4400 (c) 44
  8. 8.Best estimate of 1578 ÷ 86? (a) 180 (b) 1800 (c) 18
  9. 9.Best estimate of 5758 ÷ 72? (a) 82 (b) 820 (c) 8200
  10. 10.Best estimate of 2898 ÷ 51? (a) 580 (b) 5800 (c) 58
  11. 11.√30 to 1 decimal place? (a) 5.5 (b) 5.7 (c) 5.6 (d) 5.4
  12. 12.√87 to 1 decimal place? (a) 9.2 (b) 9.1 (c) 9.4 (d) 9.3
  13. 13.Best estimate of 1195 ÷ 44? (a) 3000 (b) 300 (c) 30
  14. 14.Best estimate of 1102 ÷ 31? (a) 370 (b) 3700 (c) 37
  15. 15.Best estimate of 1683 ÷ 46? (a) 340 (b) 3400 (c) 34
  16. 16.Best estimate of 2599 ÷ 44? (a) 65 (b) 6500 (c) 650
  17. 17.Best estimate of 4374 ÷ 71? (a) 6200 (b) 62 (c) 620
  18. 18.√66 to 1 decimal place? (a) 8.0 (b) 7.8 (c) 7.9 (d) 8.1
  19. 19.Best estimate of 3012 ÷ 37? (a) 750 (b) 7500 (c) 75
  20. 20.Best estimate of 1215 ÷ 88? (a) 140 (b) 14 (c) 1400
  21. 21.√61 to 1 decimal place? (a) 8.0 (b) 7.9 (c) 8.1 (d) 7.8
  22. 22.Best estimate of 565 ÷ 28? (a) 190 (b) 1900 (c) 19
  23. 23.Best estimate of 4364 ÷ 86? (a) 4800 (b) 480 (c) 48
  24. 24.Best estimate of 3842 ÷ 72? (a) 5500 (b) 55 (c) 550
  25. 25.Best estimate of 1291 ÷ 39? (a) 320 (b) 32 (c) 3200
  26. 26.Best estimate of 4568 ÷ 52? (a) 910 (b) 9100 (c) 91
  27. 27.√63 to 1 decimal place? (a) 7.9 (b) 8.1 (c) 8.0 (d) 7.8
  28. 28.√37 to 1 decimal place? (a) 5.8 (b) 6.1 (c) 5.9 (d) 6.0
  29. 29.√69 to 1 decimal place? (a) 8.2 (b) 8.5 (c) 8.3 (d) 8.4
  30. 30.Best estimate of 3179 ÷ 49? (a) 64 (b) 6400 (c) 640
  31. 31.Best estimate of 1845 ÷ 41? (a) 46 (b) 4600 (c) 460
  32. 32.√28 to 1 decimal place? (a) 5.5 (b) 5.2 (c) 5.4 (d) 5.3
  33. 33.Best estimate of 967 ÷ 42? (a) 24 (b) 2400 (c) 240
  34. 34.Best estimate of 1915 ÷ 62? (a) 320 (b) 32 (c) 3200
  35. 35.Best estimate of 3151 ÷ 39? (a) 79 (b) 790 (c) 7900
  36. 36.√55 to 1 decimal place? (a) 7.6 (b) 7.7 (c) 7.5 (d) 7.4
  37. 37.√67 to 1 decimal place? (a) 8.2 (b) 8.1 (c) 8.4 (d) 8.3
  38. 38.Best estimate of 4840 ÷ 76? (a) 61 (b) 6100 (c) 610
  39. 39.√40 to 1 decimal place? (a) 6.3 (b) 6.2 (c) 6.5 (d) 6.4
  40. 40.Best estimate of 3117 ÷ 66? (a) 45 (b) 450 (c) 4500

Answer key

  1. 79
  2. 58
  3. 71
  4. 7.1
  5. 5.1
  6. 7.6
  7. 44
  8. 18
  9. 82
  10. 58
  11. 5.5
  12. 9.3
  13. 30
  14. 37
  15. 34
  16. 65
  17. 62
  18. 8.1
  19. 75
  20. 14
  21. 7.8
  22. 19
  23. 48
  24. 55
  25. 32
  26. 91
  27. 7.9
  28. 6.1
  29. 8.3
  30. 64
  31. 46
  32. 5.3
  33. 24
  34. 32
  35. 79
  36. 7.4
  37. 8.2
  38. 61
  39. 6.3
  40. 45

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