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Estimating Square Roots and Division Worksheet

Mental maths lesson 27: Estimate divisions and square roots · Set 994 · 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.√38 to 1 decimal place? (a) 6.1 (b) 6.2 (c) 6.0 (d) 6.3
  2. 2.√37 to 1 decimal place? (a) 5.9 (b) 6.0 (c) 5.8 (d) 6.1
  3. 3.√94 to 1 decimal place? (a) 9.6 (b) 9.7 (c) 9.4 (d) 9.5
  4. 4.Best estimate of 4663 ÷ 52? (a) 9300 (b) 930 (c) 93
  5. 5.Best estimate of 876 ÷ 72? (a) 13 (b) 1300 (c) 130
  6. 6.Best estimate of 3668 ÷ 48? (a) 7300 (b) 73 (c) 730
  7. 7.√82 to 1 decimal place? (a) 9.1 (b) 9.2 (c) 9.3 (d) 9.0
  8. 8.Best estimate of 527 ÷ 33? (a) 1800 (b) 18 (c) 180
  9. 9.√74 to 1 decimal place? (a) 8.7 (b) 8.8 (c) 8.6 (d) 8.9
  10. 10.√87 to 1 decimal place? (a) 9.0 (b) 9.2 (c) 9.1 (d) 9.3
  11. 11.√48 to 1 decimal place? (a) 7.1 (b) 7.0 (c) 6.9 (d) 6.8
  12. 12.Best estimate of 1056 ÷ 32? (a) 35 (b) 350 (c) 3500
  13. 13.√88 to 1 decimal place? (a) 9.3 (b) 9.4 (c) 9.5 (d) 9.6
  14. 14.Best estimate of 754 ÷ 36? (a) 1900 (b) 190 (c) 19
  15. 15.√50 to 1 decimal place? (a) 7.3 (b) 7.2 (c) 7.0 (d) 7.1
  16. 16.Best estimate of 3280 ÷ 36? (a) 8200 (b) 820 (c) 82
  17. 17.Best estimate of 2000 ÷ 76? (a) 250 (b) 2500 (c) 25
  18. 18.Best estimate of 625 ÷ 44? (a) 16 (b) 1600 (c) 160
  19. 19.√78 to 1 decimal place? (a) 8.6 (b) 8.5 (c) 8.8 (d) 8.7
  20. 20.√58 to 1 decimal place? (a) 7.5 (b) 7.6 (c) 7.3 (d) 7.4
  21. 21.√80 to 1 decimal place? (a) 9.2 (b) 9.0 (c) 9.1 (d) 8.9
  22. 22.√45 to 1 decimal place? (a) 6.5 (b) 6.8 (c) 6.7 (d) 6.6
  23. 23.√32 to 1 decimal place? (a) 5.6 (b) 5.7 (c) 5.5 (d) 5.8
  24. 24.√77 to 1 decimal place? (a) 8.6 (b) 8.7 (c) 8.8 (d) 8.5
  25. 25.Best estimate of 879 ÷ 42? (a) 2200 (b) 220 (c) 22
  26. 26.Best estimate of 1744 ÷ 34? (a) 580 (b) 5800 (c) 58
  27. 27.Best estimate of 1646 ÷ 52? (a) 33 (b) 3300 (c) 330
  28. 28.√67 to 1 decimal place? (a) 8.2 (b) 8.3 (c) 8.1 (d) 8.4
  29. 29.Best estimate of 2945 ÷ 79? (a) 3700 (b) 37 (c) 370
  30. 30.√69 to 1 decimal place? (a) 8.5 (b) 8.6 (c) 8.4 (d) 8.3
  31. 31.√62 to 1 decimal place? (a) 7.9 (b) 8.1 (c) 7.8 (d) 8.0
  32. 32.√76 to 1 decimal place? (a) 8.5 (b) 8.8 (c) 8.6 (d) 8.7
  33. 33.Best estimate of 617 ÷ 26? (a) 21 (b) 210 (c) 2100
  34. 34.√47 to 1 decimal place? (a) 6.7 (b) 6.6 (c) 6.8 (d) 6.9
  35. 35.√43 to 1 decimal place? (a) 6.5 (b) 6.8 (c) 6.7 (d) 6.6
  36. 36.√90 to 1 decimal place? (a) 9.4 (b) 9.5 (c) 9.3 (d) 9.6
  37. 37.Best estimate of 2679 ÷ 46? (a) 54 (b) 540 (c) 5400
  38. 38.Best estimate of 2195 ÷ 32? (a) 73 (b) 730 (c) 7300
  39. 39.√46 to 1 decimal place? (a) 6.9 (b) 6.6 (c) 6.7 (d) 6.8
  40. 40.Best estimate of 1302 ÷ 72? (a) 190 (b) 1900 (c) 19

Answer key

  1. 6.2
  2. 6.1
  3. 9.7
  4. 93
  5. 13
  6. 73
  7. 9.1
  8. 18
  9. 8.6
  10. 9.3
  11. 6.9
  12. 35
  13. 9.4
  14. 19
  15. 7.1
  16. 82
  17. 25
  18. 16
  19. 8.8
  20. 7.6
  21. 8.9
  22. 6.7
  23. 5.7
  24. 8.8
  25. 22
  26. 58
  27. 33
  28. 8.2
  29. 37
  30. 8.3
  31. 7.9
  32. 8.7
  33. 21
  34. 6.9
  35. 6.6
  36. 9.5
  37. 54
  38. 73
  39. 6.8
  40. 19

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