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Estimating Square Roots and Division Worksheet

Mental maths lesson 27: Estimate divisions and square roots · Set 211 · 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 547 ÷ 33? (a) 18 (b) 1800 (c) 180
  2. 2.Best estimate of 5290 ÷ 71? (a) 760 (b) 7600 (c) 76
  3. 3.Best estimate of 3857 ÷ 43? (a) 9600 (b) 96 (c) 960
  4. 4.√34 to 1 decimal place? (a) 6.1 (b) 5.9 (c) 5.8 (d) 6.0
  5. 5.Best estimate of 4515 ÷ 52? (a) 9000 (b) 90 (c) 900
  6. 6.√41 to 1 decimal place? (a) 6.5 (b) 6.3 (c) 6.2 (d) 6.4
  7. 7.√74 to 1 decimal place? (a) 8.7 (b) 8.6 (c) 8.4 (d) 8.5
  8. 8.Best estimate of 2688 ÷ 63? (a) 450 (b) 4500 (c) 45
  9. 9.Best estimate of 5082 ÷ 79? (a) 64 (b) 640 (c) 6400
  10. 10.Best estimate of 4448 ÷ 54? (a) 8900 (b) 890 (c) 89
  11. 11.√35 to 1 decimal place? (a) 5.9 (b) 5.7 (c) 6.0 (d) 5.8
  12. 12.Best estimate of 2914 ÷ 59? (a) 4900 (b) 49 (c) 490
  13. 13.√24 to 1 decimal place? (a) 4.9 (b) 5.2 (c) 5.0 (d) 5.1
  14. 14.Best estimate of 1483 ÷ 21? (a) 74 (b) 740 (c) 7400
  15. 15.Best estimate of 1434 ÷ 73? (a) 2000 (b) 200 (c) 20
  16. 16.Best estimate of 4598 ÷ 59? (a) 770 (b) 7700 (c) 77
  17. 17.√51 to 1 decimal place? (a) 7.2 (b) 6.9 (c) 7.1 (d) 7.0
  18. 18.Best estimate of 1996 ÷ 29? (a) 67 (b) 670 (c) 6700
  19. 19.Best estimate of 2045 ÷ 49? (a) 410 (b) 4100 (c) 41
  20. 20.√37 to 1 decimal place? (a) 6.1 (b) 6.4 (c) 6.3 (d) 6.2
  21. 21.Best estimate of 969 ÷ 41? (a) 240 (b) 2400 (c) 24
  22. 22.√70 to 1 decimal place? (a) 8.1 (b) 8.3 (c) 8.2 (d) 8.4
  23. 23.√28 to 1 decimal place? (a) 5.1 (b) 5.2 (c) 5.4 (d) 5.3
  24. 24.√40 to 1 decimal place? (a) 6.0 (b) 6.3 (c) 6.2 (d) 6.1
  25. 25.Best estimate of 2414 ÷ 66? (a) 340 (b) 3400 (c) 34
  26. 26.√71 to 1 decimal place? (a) 8.3 (b) 8.2 (c) 8.1 (d) 8.4
  27. 27.Best estimate of 1789 ÷ 52? (a) 360 (b) 36 (c) 3600
  28. 28.Best estimate of 2330 ÷ 52? (a) 47 (b) 4700 (c) 470
  29. 29.√65 to 1 decimal place? (a) 8.0 (b) 8.1 (c) 7.8 (d) 7.9
  30. 30.√56 to 1 decimal place? (a) 7.4 (b) 7.2 (c) 7.3 (d) 7.5
  31. 31.Best estimate of 1898 ÷ 26? (a) 63 (b) 6300 (c) 630
  32. 32.√85 to 1 decimal place? (a) 9.1 (b) 9.0 (c) 8.9 (d) 9.2
  33. 33.Best estimate of 475 ÷ 21? (a) 2400 (b) 24 (c) 240
  34. 34.√26 to 1 decimal place? (a) 5.3 (b) 5.1 (c) 5.4 (d) 5.2
  35. 35.√80 to 1 decimal place? (a) 9.2 (b) 8.9 (c) 9.1 (d) 9.0
  36. 36.√76 to 1 decimal place? (a) 8.7 (b) 9.0 (c) 8.8 (d) 8.9
  37. 37.Best estimate of 3905 ÷ 41? (a) 9800 (b) 980 (c) 98
  38. 38.Best estimate of 801 ÷ 52? (a) 1600 (b) 16 (c) 160
  39. 39.Best estimate of 6557 ÷ 71? (a) 940 (b) 94 (c) 9400
  40. 40.Best estimate of 1242 ÷ 27? (a) 410 (b) 4100 (c) 41

Answer key

  1. 18
  2. 76
  3. 96
  4. 5.8
  5. 90
  6. 6.4
  7. 8.6
  8. 45
  9. 64
  10. 89
  11. 5.9
  12. 49
  13. 4.9
  14. 74
  15. 20
  16. 77
  17. 7.1
  18. 67
  19. 41
  20. 6.1
  21. 24
  22. 8.4
  23. 5.3
  24. 6.3
  25. 34
  26. 8.4
  27. 36
  28. 47
  29. 8.1
  30. 7.5
  31. 63
  32. 9.2
  33. 24
  34. 5.1
  35. 8.9
  36. 8.7
  37. 98
  38. 16
  39. 94
  40. 41

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