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Estimating Square Roots and Division Worksheet

Mental maths lesson 27: Estimate divisions and square roots · Set 552 · 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 3022 ÷ 52? (a) 60 (b) 6000 (c) 600
  2. 2.Best estimate of 2264 ÷ 32? (a) 7500 (b) 75 (c) 750
  3. 3.√29 to 1 decimal place? (a) 5.4 (b) 5.1 (c) 5.2 (d) 5.3
  4. 4.Best estimate of 1294 ÷ 72? (a) 18 (b) 1800 (c) 180
  5. 5.√63 to 1 decimal place? (a) 7.7 (b) 7.8 (c) 7.6 (d) 7.9
  6. 6.√74 to 1 decimal place? (a) 8.6 (b) 8.4 (c) 8.3 (d) 8.5
  7. 7.√82 to 1 decimal place? (a) 9.2 (b) 9.3 (c) 9.1 (d) 9.0
  8. 8.√58 to 1 decimal place? (a) 7.3 (b) 7.5 (c) 7.6 (d) 7.4
  9. 9.√26 to 1 decimal place? (a) 5.1 (b) 5.3 (c) 5.2 (d) 5.0
  10. 10.Best estimate of 2852 ÷ 33? (a) 950 (b) 95 (c) 9500
  11. 11.Best estimate of 2066 ÷ 46? (a) 410 (b) 4100 (c) 41
  12. 12.√83 to 1 decimal place? (a) 9.4 (b) 9.2 (c) 9.1 (d) 9.3
  13. 13.Best estimate of 1191 ÷ 51? (a) 2400 (b) 24 (c) 240
  14. 14.Best estimate of 1556 ÷ 57? (a) 260 (b) 26 (c) 2600
  15. 15.Best estimate of 787 ÷ 41? (a) 2000 (b) 20 (c) 200
  16. 16.Best estimate of 3920 ÷ 74? (a) 560 (b) 56 (c) 5600
  17. 17.Best estimate of 6027 ÷ 82? (a) 7500 (b) 750 (c) 75
  18. 18.Best estimate of 1939 ÷ 33? (a) 650 (b) 6500 (c) 65
  19. 19.√21 to 1 decimal place? (a) 4.4 (b) 4.3 (c) 4.6 (d) 4.5
  20. 20.Best estimate of 3659 ÷ 76? (a) 46 (b) 4600 (c) 460
  21. 21.Best estimate of 3158 ÷ 46? (a) 6300 (b) 630 (c) 63
  22. 22.Best estimate of 3503 ÷ 42? (a) 8800 (b) 880 (c) 88
  23. 23.Best estimate of 474 ÷ 23? (a) 24 (b) 2400 (c) 240
  24. 24.Best estimate of 1036 ÷ 78? (a) 130 (b) 1300 (c) 13
  25. 25.√55 to 1 decimal place? (a) 7.6 (b) 7.5 (c) 7.4 (d) 7.7
  26. 26.√62 to 1 decimal place? (a) 8.1 (b) 7.9 (c) 8.2 (d) 8.0
  27. 27.Best estimate of 4807 ÷ 61? (a) 8000 (b) 800 (c) 80
  28. 28.√23 to 1 decimal place? (a) 4.8 (b) 4.9 (c) 5.1 (d) 5.0
  29. 29.Best estimate of 4173 ÷ 72? (a) 6000 (b) 60 (c) 600
  30. 30.Best estimate of 1783 ÷ 41? (a) 450 (b) 45 (c) 4500
  31. 31.√84 to 1 decimal place? (a) 9.1 (b) 9.2 (c) 9.3 (d) 9.0
  32. 32.Best estimate of 2836 ÷ 71? (a) 4100 (b) 410 (c) 41
  33. 33.Best estimate of 1581 ÷ 66? (a) 23 (b) 230 (c) 2300
  34. 34.Best estimate of 1909 ÷ 36? (a) 4800 (b) 48 (c) 480
  35. 35.Best estimate of 2621 ÷ 34? (a) 870 (b) 87 (c) 8700
  36. 36.√92 to 1 decimal place? (a) 9.8 (b) 9.6 (c) 9.9 (d) 9.7
  37. 37.√67 to 1 decimal place? (a) 8.0 (b) 8.2 (c) 8.1 (d) 7.9
  38. 38.Best estimate of 6028 ÷ 72? (a) 860 (b) 8600 (c) 86
  39. 39.Best estimate of 4329 ÷ 46? (a) 8700 (b) 870 (c) 87
  40. 40.Best estimate of 820 ÷ 26? (a) 2700 (b) 270 (c) 27

Answer key

  1. 60
  2. 75
  3. 5.4
  4. 18
  5. 7.9
  6. 8.6
  7. 9.1
  8. 7.6
  9. 5.1
  10. 95
  11. 41
  12. 9.1
  13. 24
  14. 26
  15. 20
  16. 56
  17. 75
  18. 65
  19. 4.6
  20. 46
  21. 63
  22. 88
  23. 24
  24. 13
  25. 7.4
  26. 7.9
  27. 80
  28. 4.8
  29. 60
  30. 45
  31. 9.2
  32. 41
  33. 23
  34. 48
  35. 87
  36. 9.6
  37. 8.2
  38. 86
  39. 87
  40. 27

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