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Estimating Square Roots and Division Worksheet

Mental maths lesson 27: Estimate divisions and square roots · Set 893 · 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 2296 ÷ 36? (a) 5700 (b) 570 (c) 57
  2. 2.Best estimate of 2073 ÷ 63? (a) 350 (b) 3500 (c) 35
  3. 3.√45 to 1 decimal place? (a) 6.7 (b) 6.6 (c) 6.9 (d) 6.8
  4. 4.√65 to 1 decimal place? (a) 8.0 (b) 7.9 (c) 7.8 (d) 8.1
  5. 5.√31 to 1 decimal place? (a) 5.7 (b) 5.8 (c) 5.6 (d) 5.9
  6. 6.Best estimate of 3932 ÷ 41? (a) 9800 (b) 98 (c) 980
  7. 7.Best estimate of 1320 ÷ 32? (a) 4400 (b) 440 (c) 44
  8. 8.Best estimate of 740 ÷ 32? (a) 25 (b) 2500 (c) 250
  9. 9.√98 to 1 decimal place? (a) 10.0 (b) 10.1 (c) 9.9 (d) 10.2
  10. 10.Best estimate of 1465 ÷ 28? (a) 490 (b) 4900 (c) 49
  11. 11.Best estimate of 3096 ÷ 73? (a) 440 (b) 44 (c) 4400
  12. 12.√37 to 1 decimal place? (a) 6.0 (b) 5.9 (c) 6.2 (d) 6.1
  13. 13.Best estimate of 3853 ÷ 89? (a) 4300 (b) 430 (c) 43
  14. 14.Best estimate of 6121 ÷ 69? (a) 870 (b) 87 (c) 8700
  15. 15.Best estimate of 2576 ÷ 44? (a) 640 (b) 64 (c) 6400
  16. 16.√29 to 1 decimal place? (a) 5.5 (b) 5.4 (c) 5.3 (d) 5.2
  17. 17.Best estimate of 3883 ÷ 63? (a) 650 (b) 6500 (c) 65
  18. 18.√50 to 1 decimal place? (a) 7.3 (b) 7.1 (c) 7.4 (d) 7.2
  19. 19.Best estimate of 939 ÷ 26? (a) 310 (b) 3100 (c) 31
  20. 20.√58 to 1 decimal place? (a) 7.6 (b) 7.4 (c) 7.5 (d) 7.7
  21. 21.√79 to 1 decimal place? (a) 8.7 (b) 9.0 (c) 8.8 (d) 8.9
  22. 22.Best estimate of 612 ÷ 22? (a) 310 (b) 3100 (c) 31
  23. 23.Best estimate of 5950 ÷ 69? (a) 85 (b) 8500 (c) 850
  24. 24.Best estimate of 2496 ÷ 53? (a) 5000 (b) 500 (c) 50
  25. 25.√70 to 1 decimal place? (a) 8.5 (b) 8.3 (c) 8.2 (d) 8.4
  26. 26.Best estimate of 2089 ÷ 46? (a) 42 (b) 420 (c) 4200
  27. 27.√32 to 1 decimal place? (a) 5.8 (b) 6.0 (c) 5.9 (d) 5.7
  28. 28.Best estimate of 562 ÷ 24? (a) 28 (b) 2800 (c) 280
  29. 29.√27 to 1 decimal place? (a) 5.3 (b) 5.5 (c) 5.2 (d) 5.4
  30. 30.√94 to 1 decimal place? (a) 9.7 (b) 10.0 (c) 9.9 (d) 9.8
  31. 31.Best estimate of 1457 ÷ 36? (a) 36 (b) 360 (c) 3600
  32. 32.Best estimate of 7600 ÷ 89? (a) 840 (b) 84 (c) 8400
  33. 33.Best estimate of 2166 ÷ 76? (a) 270 (b) 2700 (c) 27
  34. 34.Best estimate of 2628 ÷ 66? (a) 380 (b) 38 (c) 3800
  35. 35.Best estimate of 2991 ÷ 38? (a) 750 (b) 7500 (c) 75
  36. 36.√92 to 1 decimal place? (a) 9.6 (b) 9.7 (c) 9.4 (d) 9.5
  37. 37.√46 to 1 decimal place? (a) 6.8 (b) 6.7 (c) 6.6 (d) 6.5
  38. 38.Best estimate of 2711 ÷ 52? (a) 540 (b) 54 (c) 5400
  39. 39.Best estimate of 552 ÷ 21? (a) 2800 (b) 28 (c) 280
  40. 40.Best estimate of 812 ÷ 26? (a) 2700 (b) 27 (c) 270

Answer key

  1. 57
  2. 35
  3. 6.7
  4. 8.1
  5. 5.6
  6. 98
  7. 44
  8. 25
  9. 9.9
  10. 49
  11. 44
  12. 6.1
  13. 43
  14. 87
  15. 64
  16. 5.4
  17. 65
  18. 7.1
  19. 31
  20. 7.6
  21. 8.9
  22. 31
  23. 85
  24. 50
  25. 8.4
  26. 42
  27. 5.7
  28. 28
  29. 5.2
  30. 9.7
  31. 36
  32. 84
  33. 27
  34. 38
  35. 75
  36. 9.6
  37. 6.8
  38. 54
  39. 28
  40. 27

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