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Estimating Square Roots and Division Worksheet

Mental maths lesson 27: Estimate divisions and square roots · Set 261 · 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.√76 to 1 decimal place? (a) 9.0 (b) 8.8 (c) 8.9 (d) 8.7
  2. 2.√41 to 1 decimal place? (a) 6.1 (b) 6.3 (c) 6.2 (d) 6.4
  3. 3.Best estimate of 4257 ÷ 76? (a) 530 (b) 53 (c) 5300
  4. 4.Best estimate of 3054 ÷ 32? (a) 1020 (b) 10200 (c) 102
  5. 5.Best estimate of 2768 ÷ 32? (a) 920 (b) 9200 (c) 92
  6. 6.√50 to 1 decimal place? (a) 7.2 (b) 6.9 (c) 7.0 (d) 7.1
  7. 7.Best estimate of 2712 ÷ 44? (a) 6800 (b) 680 (c) 68
  8. 8.√37 to 1 decimal place? (a) 6.1 (b) 5.8 (c) 5.9 (d) 6.0
  9. 9.Best estimate of 3406 ÷ 72? (a) 49 (b) 490 (c) 4900
  10. 10.Best estimate of 3024 ÷ 49? (a) 60 (b) 600 (c) 6000
  11. 11.√26 to 1 decimal place? (a) 4.9 (b) 5.0 (c) 5.1 (d) 4.8
  12. 12.√94 to 1 decimal place? (a) 10.0 (b) 9.7 (c) 9.8 (d) 9.9
  13. 13.Best estimate of 952 ÷ 36? (a) 240 (b) 24 (c) 2400
  14. 14.√66 to 1 decimal place? (a) 8.4 (b) 8.3 (c) 8.2 (d) 8.1
  15. 15.√47 to 1 decimal place? (a) 7.1 (b) 7.0 (c) 6.9 (d) 7.2
  16. 16.Best estimate of 1507 ÷ 52? (a) 300 (b) 3000 (c) 30
  17. 17.Best estimate of 1579 ÷ 57? (a) 2600 (b) 260 (c) 26
  18. 18.Best estimate of 6046 ÷ 78? (a) 7600 (b) 760 (c) 76
  19. 19.√65 to 1 decimal place? (a) 8.2 (b) 8.0 (c) 8.1 (d) 8.3
  20. 20.√22 to 1 decimal place? (a) 4.7 (b) 4.5 (c) 4.6 (d) 4.4
  21. 21.Best estimate of 2274 ÷ 66? (a) 32 (b) 320 (c) 3200
  22. 22.√82 to 1 decimal place? (a) 9.1 (b) 9.2 (c) 9.3 (d) 9.0
  23. 23.√92 to 1 decimal place? (a) 9.7 (b) 9.8 (c) 9.9 (d) 9.6
  24. 24.√40 to 1 decimal place? (a) 6.3 (b) 6.1 (c) 6.2 (d) 6.4
  25. 25.Best estimate of 1705 ÷ 63? (a) 280 (b) 2800 (c) 28
  26. 26.√58 to 1 decimal place? (a) 7.7 (b) 7.8 (c) 7.5 (d) 7.6
  27. 27.√38 to 1 decimal place? (a) 6.3 (b) 6.2 (c) 6.1 (d) 6.0
  28. 28.√34 to 1 decimal place? (a) 5.8 (b) 5.7 (c) 5.9 (d) 5.6
  29. 29.Best estimate of 893 ÷ 41? (a) 2200 (b) 220 (c) 22
  30. 30.√44 to 1 decimal place? (a) 6.8 (b) 6.6 (c) 6.5 (d) 6.7
  31. 31.√52 to 1 decimal place? (a) 7.2 (b) 7.4 (c) 7.3 (d) 7.1
  32. 32.√78 to 1 decimal place? (a) 9.0 (b) 8.8 (c) 8.9 (d) 9.1
  33. 33.√88 to 1 decimal place? (a) 9.3 (b) 9.4 (c) 9.5 (d) 9.6
  34. 34.Best estimate of 545 ÷ 23? (a) 270 (b) 27 (c) 2700
  35. 35.Best estimate of 1038 ÷ 26? (a) 3500 (b) 350 (c) 35
  36. 36.Best estimate of 1440 ÷ 32? (a) 480 (b) 48 (c) 4800
  37. 37.Best estimate of 948 ÷ 38? (a) 2400 (b) 240 (c) 24
  38. 38.Best estimate of 575 ÷ 27? (a) 190 (b) 19 (c) 1900
  39. 39.√96 to 1 decimal place? (a) 9.8 (b) 9.9 (c) 10.0 (d) 9.7
  40. 40.Best estimate of 2326 ÷ 64? (a) 3900 (b) 39 (c) 390

Answer key

  1. 8.7
  2. 6.4
  3. 53
  4. 102
  5. 92
  6. 7.1
  7. 68
  8. 6.1
  9. 49
  10. 60
  11. 5.1
  12. 9.7
  13. 24
  14. 8.1
  15. 6.9
  16. 30
  17. 26
  18. 76
  19. 8.1
  20. 4.7
  21. 32
  22. 9.1
  23. 9.6
  24. 6.3
  25. 28
  26. 7.6
  27. 6.2
  28. 5.8
  29. 22
  30. 6.6
  31. 7.2
  32. 8.8
  33. 9.4
  34. 27
  35. 35
  36. 48
  37. 24
  38. 19
  39. 9.8
  40. 39

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