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Estimating Square Roots and Division Worksheet

Mental maths lesson 27: Estimate divisions and square roots · Set 337 · 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 1431 ÷ 49? (a) 2900 (b) 290 (c) 29
  2. 2.Best estimate of 583 ÷ 44? (a) 15 (b) 150 (c) 1500
  3. 3.Best estimate of 759 ÷ 58? (a) 130 (b) 13 (c) 1300
  4. 4.√94 to 1 decimal place? (a) 9.7 (b) 9.5 (c) 9.6 (d) 9.8
  5. 5.√26 to 1 decimal place? (a) 4.8 (b) 5.1 (c) 5.0 (d) 4.9
  6. 6.√71 to 1 decimal place? (a) 8.6 (b) 8.5 (c) 8.7 (d) 8.4
  7. 7.Best estimate of 3042 ÷ 39? (a) 76 (b) 760 (c) 7600
  8. 8.Best estimate of 1737 ÷ 26? (a) 58 (b) 580 (c) 5800
  9. 9.√50 to 1 decimal place? (a) 7.0 (b) 6.8 (c) 7.1 (d) 6.9
  10. 10.√32 to 1 decimal place? (a) 5.5 (b) 5.6 (c) 5.7 (d) 5.8
  11. 11.Best estimate of 1499 ÷ 48? (a) 300 (b) 3000 (c) 30
  12. 12.Best estimate of 1766 ÷ 26? (a) 5900 (b) 59 (c) 590
  13. 13.Best estimate of 1589 ÷ 36? (a) 40 (b) 400 (c) 4000
  14. 14.√92 to 1 decimal place? (a) 9.6 (b) 9.4 (c) 9.7 (d) 9.5
  15. 15.√82 to 1 decimal place? (a) 9.0 (b) 9.1 (c) 9.2 (d) 8.9
  16. 16.Best estimate of 1115 ÷ 32? (a) 37 (b) 3700 (c) 370
  17. 17.Best estimate of 479 ÷ 34? (a) 160 (b) 1600 (c) 16
  18. 18.√23 to 1 decimal place? (a) 4.8 (b) 4.6 (c) 4.9 (d) 4.7
  19. 19.Best estimate of 664 ÷ 36? (a) 17 (b) 170 (c) 1700
  20. 20.Best estimate of 1390 ÷ 62? (a) 23 (b) 2300 (c) 230
  21. 21.√35 to 1 decimal place? (a) 5.7 (b) 5.6 (c) 5.8 (d) 5.9
  22. 22.Best estimate of 550 ÷ 23? (a) 2800 (b) 28 (c) 280
  23. 23.Best estimate of 2738 ÷ 36? (a) 68 (b) 6800 (c) 680
  24. 24.√72 to 1 decimal place? (a) 8.5 (b) 8.6 (c) 8.8 (d) 8.7
  25. 25.Best estimate of 3728 ÷ 46? (a) 750 (b) 75 (c) 7500
  26. 26.√85 to 1 decimal place? (a) 9.1 (b) 9.3 (c) 9.0 (d) 9.2
  27. 27.Best estimate of 2918 ÷ 39? (a) 730 (b) 7300 (c) 73
  28. 28.Best estimate of 1664 ÷ 72? (a) 24 (b) 2400 (c) 240
  29. 29.Best estimate of 1144 ÷ 47? (a) 230 (b) 2300 (c) 23
  30. 30.√44 to 1 decimal place? (a) 6.6 (b) 6.5 (c) 6.4 (d) 6.7
  31. 31.Best estimate of 6499 ÷ 68? (a) 9300 (b) 930 (c) 93
  32. 32.Best estimate of 1946 ÷ 82? (a) 2400 (b) 24 (c) 240
  33. 33.Best estimate of 4435 ÷ 71? (a) 63 (b) 6300 (c) 630
  34. 34.√98 to 1 decimal place? (a) 9.6 (b) 9.8 (c) 9.7 (d) 9.9
  35. 35.√43 to 1 decimal place? (a) 6.7 (b) 6.4 (c) 6.5 (d) 6.6
  36. 36.Best estimate of 1307 ÷ 39? (a) 3300 (b) 330 (c) 33
  37. 37.Best estimate of 2747 ÷ 34? (a) 9200 (b) 920 (c) 92
  38. 38.√63 to 1 decimal place? (a) 7.9 (b) 8.0 (c) 7.8 (d) 8.1
  39. 39.√37 to 1 decimal place? (a) 6.4 (b) 6.3 (c) 6.2 (d) 6.1
  40. 40.√38 to 1 decimal place? (a) 6.5 (b) 6.2 (c) 6.4 (d) 6.3

Answer key

  1. 29
  2. 15
  3. 13
  4. 9.7
  5. 5.1
  6. 8.4
  7. 76
  8. 58
  9. 7.1
  10. 5.7
  11. 30
  12. 59
  13. 40
  14. 9.6
  15. 9.1
  16. 37
  17. 16
  18. 4.8
  19. 17
  20. 23
  21. 5.9
  22. 28
  23. 68
  24. 8.5
  25. 75
  26. 9.2
  27. 73
  28. 24
  29. 23
  30. 6.6
  31. 93
  32. 24
  33. 63
  34. 9.9
  35. 6.6
  36. 33
  37. 92
  38. 7.9
  39. 6.1
  40. 6.2

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