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Estimating Square Roots and Division Worksheet

Mental maths lesson 27: Estimate divisions and square roots · Set 592 · 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 2862 ÷ 51? (a) 570 (b) 5700 (c) 57
  2. 2.√50 to 1 decimal place? (a) 6.9 (b) 7.1 (c) 7.0 (d) 6.8
  3. 3.Best estimate of 818 ÷ 64? (a) 1400 (b) 14 (c) 140
  4. 4.Best estimate of 5838 ÷ 76? (a) 7300 (b) 73 (c) 730
  5. 5.Best estimate of 3234 ÷ 88? (a) 36 (b) 3600 (c) 360
  6. 6.Best estimate of 2489 ÷ 56? (a) 41 (b) 410 (c) 4100
  7. 7.√87 to 1 decimal place? (a) 9.2 (b) 9.4 (c) 9.3 (d) 9.1
  8. 8.Best estimate of 3049 ÷ 63? (a) 5100 (b) 510 (c) 51
  9. 9.Best estimate of 5211 ÷ 56? (a) 870 (b) 8700 (c) 87
  10. 10.Best estimate of 3412 ÷ 79? (a) 43 (b) 4300 (c) 430
  11. 11.Best estimate of 3033 ÷ 38? (a) 76 (b) 7600 (c) 760
  12. 12.√92 to 1 decimal place? (a) 9.4 (b) 9.3 (c) 9.6 (d) 9.5
  13. 13.Best estimate of 838 ÷ 27? (a) 280 (b) 28 (c) 2800
  14. 14.√62 to 1 decimal place? (a) 7.9 (b) 7.8 (c) 8.0 (d) 7.7
  15. 15.√30 to 1 decimal place? (a) 5.4 (b) 5.3 (c) 5.5 (d) 5.6
  16. 16.Best estimate of 1820 ÷ 77? (a) 2300 (b) 230 (c) 23
  17. 17.√69 to 1 decimal place? (a) 8.2 (b) 8.5 (c) 8.4 (d) 8.3
  18. 18.√82 to 1 decimal place? (a) 9.0 (b) 9.1 (c) 8.8 (d) 8.9
  19. 19.Best estimate of 1911 ÷ 23? (a) 9600 (b) 96 (c) 960
  20. 20.Best estimate of 1171 ÷ 39? (a) 29 (b) 290 (c) 2900
  21. 21.Best estimate of 1247 ÷ 32? (a) 42 (b) 4200 (c) 420
  22. 22.Best estimate of 1702 ÷ 61? (a) 28 (b) 280 (c) 2800
  23. 23.Best estimate of 1478 ÷ 66? (a) 21 (b) 210 (c) 2100
  24. 24.√67 to 1 decimal place? (a) 8.0 (b) 7.9 (c) 8.2 (d) 8.1
  25. 25.Best estimate of 3606 ÷ 52? (a) 7200 (b) 720 (c) 72
  26. 26.√55 to 1 decimal place? (a) 7.3 (b) 7.4 (c) 7.2 (d) 7.5
  27. 27.√96 to 1 decimal place? (a) 9.9 (b) 9.7 (c) 9.8 (d) 10.0
  28. 28.√79 to 1 decimal place? (a) 9.0 (b) 8.7 (c) 8.9 (d) 8.8
  29. 29.Best estimate of 6345 ÷ 73? (a) 91 (b) 9100 (c) 910
  30. 30.Best estimate of 8010 ÷ 89? (a) 8900 (b) 890 (c) 89
  31. 31.Best estimate of 3041 ÷ 34? (a) 101 (b) 1010 (c) 10100
  32. 32.Best estimate of 4334 ÷ 76? (a) 540 (b) 54 (c) 5400
  33. 33.√98 to 1 decimal place? (a) 9.7 (b) 9.8 (c) 9.6 (d) 9.9
  34. 34.√47 to 1 decimal place? (a) 7.2 (b) 6.9 (c) 7.1 (d) 7.0
  35. 35.Best estimate of 1080 ÷ 32? (a) 36 (b) 360 (c) 3600
  36. 36.Best estimate of 1808 ÷ 27? (a) 60 (b) 600 (c) 6000
  37. 37.Best estimate of 423 ÷ 29? (a) 1400 (b) 140 (c) 14
  38. 38.Best estimate of 3414 ÷ 62? (a) 5700 (b) 570 (c) 57
  39. 39.Best estimate of 2546 ÷ 59? (a) 42 (b) 420 (c) 4200
  40. 40.Best estimate of 2288 ÷ 62? (a) 3800 (b) 38 (c) 380

Answer key

  1. 57
  2. 7.1
  3. 14
  4. 73
  5. 36
  6. 41
  7. 9.3
  8. 51
  9. 87
  10. 43
  11. 76
  12. 9.6
  13. 28
  14. 7.9
  15. 5.5
  16. 23
  17. 8.3
  18. 9.1
  19. 96
  20. 29
  21. 42
  22. 28
  23. 21
  24. 8.2
  25. 72
  26. 7.4
  27. 9.8
  28. 8.9
  29. 91
  30. 89
  31. 101
  32. 54
  33. 9.9
  34. 6.9
  35. 36
  36. 60
  37. 14
  38. 57
  39. 42
  40. 38

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