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Estimating Square Roots and Division Worksheet

Mental maths lesson 27: Estimate divisions and square roots · Set 801 · 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 4974 ÷ 56? (a) 8300 (b) 830 (c) 83
  2. 2.Best estimate of 2281 ÷ 31? (a) 760 (b) 7600 (c) 76
  3. 3.Best estimate of 3271 ÷ 83? (a) 410 (b) 41 (c) 4100
  4. 4.Best estimate of 2511 ÷ 28? (a) 8400 (b) 84 (c) 840
  5. 5.Best estimate of 3872 ÷ 62? (a) 65 (b) 650 (c) 6500
  6. 6.Best estimate of 3545 ÷ 38? (a) 8900 (b) 890 (c) 89
  7. 7.Best estimate of 1301 ÷ 21? (a) 6500 (b) 65 (c) 650
  8. 8.√72 to 1 decimal place? (a) 8.3 (b) 8.2 (c) 8.4 (d) 8.5
  9. 9.√92 to 1 decimal place? (a) 9.9 (b) 9.7 (c) 9.6 (d) 9.8
  10. 10.Best estimate of 4373 ÷ 48? (a) 8700 (b) 87 (c) 870
  11. 11.√46 to 1 decimal place? (a) 6.5 (b) 6.6 (c) 6.7 (d) 6.8
  12. 12.Best estimate of 668 ÷ 46? (a) 1300 (b) 13 (c) 130
  13. 13.Best estimate of 2212 ÷ 69? (a) 32 (b) 3200 (c) 320
  14. 14.√62 to 1 decimal place? (a) 7.6 (b) 7.8 (c) 7.9 (d) 7.7
  15. 15.Best estimate of 1534 ÷ 87? (a) 170 (b) 17 (c) 1700
  16. 16.Best estimate of 4072 ÷ 79? (a) 51 (b) 5100 (c) 510
  17. 17.Best estimate of 6783 ÷ 77? (a) 850 (b) 85 (c) 8500
  18. 18.Best estimate of 1122 ÷ 33? (a) 37 (b) 3700 (c) 370
  19. 19.√88 to 1 decimal place? (a) 9.3 (b) 9.4 (c) 9.1 (d) 9.2
  20. 20.√34 to 1 decimal place? (a) 5.8 (b) 5.6 (c) 5.5 (d) 5.7
  21. 21.Best estimate of 3140 ÷ 37? (a) 79 (b) 790 (c) 7900
  22. 22.Best estimate of 5866 ÷ 62? (a) 98 (b) 9800 (c) 980
  23. 23.Best estimate of 4240 ÷ 88? (a) 4700 (b) 47 (c) 470
  24. 24.√66 to 1 decimal place? (a) 8.3 (b) 8.2 (c) 8.0 (d) 8.1
  25. 25.Best estimate of 1496 ÷ 53? (a) 30 (b) 3000 (c) 300
  26. 26.Best estimate of 2722 ÷ 76? (a) 340 (b) 34 (c) 3400
  27. 27.Best estimate of 1229 ÷ 33? (a) 4100 (b) 41 (c) 410
  28. 28.Best estimate of 1754 ÷ 81? (a) 2200 (b) 22 (c) 220
  29. 29.Best estimate of 1365 ÷ 37? (a) 340 (b) 34 (c) 3400
  30. 30.Best estimate of 1264 ÷ 21? (a) 6300 (b) 63 (c) 630
  31. 31.Best estimate of 8259 ÷ 89? (a) 920 (b) 9200 (c) 92
  32. 32.Best estimate of 2624 ÷ 52? (a) 5200 (b) 520 (c) 52
  33. 33.Best estimate of 2595 ÷ 32? (a) 870 (b) 87 (c) 8700
  34. 34.Best estimate of 1834 ÷ 38? (a) 460 (b) 4600 (c) 46
  35. 35.Best estimate of 3942 ÷ 42? (a) 9900 (b) 99 (c) 990
  36. 36.√31 to 1 decimal place? (a) 5.3 (b) 5.4 (c) 5.5 (d) 5.6
  37. 37.Best estimate of 726 ÷ 27? (a) 2400 (b) 240 (c) 24
  38. 38.Best estimate of 1445 ÷ 54? (a) 29 (b) 2900 (c) 290
  39. 39.Best estimate of 1204 ÷ 57? (a) 2000 (b) 20 (c) 200
  40. 40.Best estimate of 3561 ÷ 59? (a) 590 (b) 5900 (c) 59

Answer key

  1. 83
  2. 76
  3. 41
  4. 84
  5. 65
  6. 89
  7. 65
  8. 8.5
  9. 9.6
  10. 87
  11. 6.8
  12. 13
  13. 32
  14. 7.9
  15. 17
  16. 51
  17. 85
  18. 37
  19. 9.4
  20. 5.8
  21. 79
  22. 98
  23. 47
  24. 8.1
  25. 30
  26. 34
  27. 41
  28. 22
  29. 34
  30. 63
  31. 92
  32. 52
  33. 87
  34. 46
  35. 99
  36. 5.6
  37. 24
  38. 29
  39. 20
  40. 59

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