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Estimating Square Roots and Division Worksheet

Mental maths lesson 27: Estimate divisions and square roots · Set 526 · 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 3313 ÷ 56? (a) 550 (b) 55 (c) 5500
  2. 2.√80 to 1 decimal place? (a) 9.0 (b) 9.1 (c) 9.2 (d) 8.9
  3. 3.√94 to 1 decimal place? (a) 9.6 (b) 9.7 (c) 9.5 (d) 9.8
  4. 4.√31 to 1 decimal place? (a) 5.6 (b) 5.9 (c) 5.7 (d) 5.8
  5. 5.Best estimate of 867 ÷ 24? (a) 430 (b) 43 (c) 4300
  6. 6.Best estimate of 4915 ÷ 74? (a) 700 (b) 7000 (c) 70
  7. 7.Best estimate of 437 ÷ 23? (a) 2200 (b) 22 (c) 220
  8. 8.Best estimate of 3292 ÷ 56? (a) 550 (b) 5500 (c) 55
  9. 9.√82 to 1 decimal place? (a) 8.9 (b) 9.2 (c) 9.0 (d) 9.1
  10. 10.Best estimate of 2071 ÷ 27? (a) 690 (b) 6900 (c) 69
  11. 11.√34 to 1 decimal place? (a) 5.7 (b) 5.5 (c) 5.8 (d) 5.6
  12. 12.√26 to 1 decimal place? (a) 5.1 (b) 5.3 (c) 5.2 (d) 5.4
  13. 13.Best estimate of 1339 ÷ 34? (a) 450 (b) 4500 (c) 45
  14. 14.Best estimate of 4829 ÷ 89? (a) 540 (b) 5400 (c) 54
  15. 15.Best estimate of 993 ÷ 21? (a) 50 (b) 500 (c) 5000
  16. 16.Best estimate of 4285 ÷ 48? (a) 860 (b) 86 (c) 8600
  17. 17.√30 to 1 decimal place? (a) 5.3 (b) 5.2 (c) 5.4 (d) 5.5
  18. 18.√83 to 1 decimal place? (a) 9.1 (b) 9.2 (c) 9.0 (d) 8.9
  19. 19.√29 to 1 decimal place? (a) 5.6 (b) 5.3 (c) 5.4 (d) 5.5
  20. 20.Best estimate of 3240 ÷ 49? (a) 6500 (b) 65 (c) 650
  21. 21.Best estimate of 1612 ÷ 63? (a) 27 (b) 270 (c) 2700
  22. 22.√52 to 1 decimal place? (a) 7.3 (b) 7.1 (c) 7.4 (d) 7.2
  23. 23.Best estimate of 4394 ÷ 61? (a) 730 (b) 7300 (c) 73
  24. 24.Best estimate of 1228 ÷ 27? (a) 41 (b) 410 (c) 4100
  25. 25.Best estimate of 6313 ÷ 67? (a) 900 (b) 9000 (c) 90
  26. 26.√58 to 1 decimal place? (a) 7.5 (b) 7.7 (c) 7.8 (d) 7.6
  27. 27.√65 to 1 decimal place? (a) 8.3 (b) 8.0 (c) 8.2 (d) 8.1
  28. 28.√56 to 1 decimal place? (a) 7.3 (b) 7.2 (c) 7.4 (d) 7.5
  29. 29.√22 to 1 decimal place? (a) 4.9 (b) 5.0 (c) 4.7 (d) 4.8
  30. 30.Best estimate of 4080 ÷ 49? (a) 8200 (b) 82 (c) 820
  31. 31.√85 to 1 decimal place? (a) 9.3 (b) 9.1 (c) 9.2 (d) 9.4
  32. 32.√62 to 1 decimal place? (a) 8.1 (b) 8.2 (c) 8.0 (d) 7.9
  33. 33.Best estimate of 1765 ÷ 58? (a) 29 (b) 290 (c) 2900
  34. 34.Best estimate of 1928 ÷ 39? (a) 480 (b) 4800 (c) 48
  35. 35.√40 to 1 decimal place? (a) 6.2 (b) 6.3 (c) 6.1 (d) 6.0
  36. 36.Best estimate of 1214 ÷ 27? (a) 40 (b) 400 (c) 4000
  37. 37.Best estimate of 4813 ÷ 76? (a) 6000 (b) 600 (c) 60
  38. 38.Best estimate of 1650 ÷ 32? (a) 5500 (b) 55 (c) 550
  39. 39.Best estimate of 1777 ÷ 46? (a) 360 (b) 36 (c) 3600
  40. 40.√79 to 1 decimal place? (a) 9.2 (b) 8.9 (c) 9.0 (d) 9.1

Answer key

  1. 55
  2. 8.9
  3. 9.7
  4. 5.6
  5. 43
  6. 70
  7. 22
  8. 55
  9. 9.1
  10. 69
  11. 5.8
  12. 5.1
  13. 45
  14. 54
  15. 50
  16. 86
  17. 5.5
  18. 9.1
  19. 5.4
  20. 65
  21. 27
  22. 7.2
  23. 73
  24. 41
  25. 90
  26. 7.6
  27. 8.1
  28. 7.5
  29. 4.7
  30. 82
  31. 9.2
  32. 7.9
  33. 29
  34. 48
  35. 6.3
  36. 40
  37. 60
  38. 55
  39. 36
  40. 8.9

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