← Estimate divisions and square roots lesson New set →

Estimating Square Roots and Division Worksheet

Mental maths lesson 27: Estimate divisions and square roots · Set 849 · 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 5718 ÷ 73? (a) 82 (b) 820 (c) 8200
  2. 2.√23 to 1 decimal place? (a) 4.7 (b) 4.6 (c) 4.8 (d) 4.9
  3. 3.√98 to 1 decimal place? (a) 9.9 (b) 9.7 (c) 9.6 (d) 9.8
  4. 4.Best estimate of 3706 ÷ 39? (a) 930 (b) 93 (c) 9300
  5. 5.√40 to 1 decimal place? (a) 6.1 (b) 6.4 (c) 6.2 (d) 6.3
  6. 6.Best estimate of 3539 ÷ 52? (a) 71 (b) 7100 (c) 710
  7. 7.Best estimate of 408 ÷ 27? (a) 140 (b) 14 (c) 1400
  8. 8.Best estimate of 1605 ÷ 22? (a) 800 (b) 80 (c) 8000
  9. 9.Best estimate of 2644 ÷ 72? (a) 38 (b) 380 (c) 3800
  10. 10.√74 to 1 decimal place? (a) 8.7 (b) 8.9 (c) 8.8 (d) 8.6
  11. 11.Best estimate of 1859 ÷ 83? (a) 23 (b) 230 (c) 2300
  12. 12.Best estimate of 605 ÷ 28? (a) 20 (b) 200 (c) 2000
  13. 13.√50 to 1 decimal place? (a) 7.4 (b) 7.3 (c) 7.2 (d) 7.1
  14. 14.Best estimate of 5544 ÷ 58? (a) 9200 (b) 920 (c) 92
  15. 15.Best estimate of 3947 ÷ 42? (a) 990 (b) 9900 (c) 99
  16. 16.Best estimate of 3806 ÷ 53? (a) 7600 (b) 760 (c) 76
  17. 17.Best estimate of 2123 ÷ 49? (a) 4200 (b) 420 (c) 42
  18. 18.√59 to 1 decimal place? (a) 7.7 (b) 7.5 (c) 7.8 (d) 7.6
  19. 19.Best estimate of 5769 ÷ 64? (a) 960 (b) 96 (c) 9600
  20. 20.Best estimate of 1900 ÷ 21? (a) 95 (b) 9500 (c) 950
  21. 21.√55 to 1 decimal place? (a) 7.3 (b) 7.5 (c) 7.4 (d) 7.6
  22. 22.Best estimate of 2675 ÷ 86? (a) 3000 (b) 30 (c) 300
  23. 23.Best estimate of 4045 ÷ 64? (a) 670 (b) 67 (c) 6700
  24. 24.√75 to 1 decimal place? (a) 8.9 (b) 9.0 (c) 8.7 (d) 8.8
  25. 25.Best estimate of 1128 ÷ 62? (a) 1900 (b) 190 (c) 19
  26. 26.Best estimate of 4945 ÷ 74? (a) 7100 (b) 710 (c) 71
  27. 27.Best estimate of 3067 ÷ 77? (a) 380 (b) 38 (c) 3800
  28. 28.√89 to 1 decimal place? (a) 9.2 (b) 9.4 (c) 9.3 (d) 9.5
  29. 29.Best estimate of 1805 ÷ 32? (a) 600 (b) 6000 (c) 60
  30. 30.Best estimate of 3122 ÷ 48? (a) 620 (b) 6200 (c) 62
  31. 31.√31 to 1 decimal place? (a) 5.7 (b) 5.8 (c) 5.6 (d) 5.5
  32. 32.Best estimate of 3388 ÷ 66? (a) 480 (b) 4800 (c) 48
  33. 33.Best estimate of 1401 ÷ 86? (a) 16 (b) 160 (c) 1600
  34. 34.√67 to 1 decimal place? (a) 8.1 (b) 8.0 (c) 8.3 (d) 8.2
  35. 35.Best estimate of 709 ÷ 23? (a) 350 (b) 35 (c) 3500
  36. 36.Best estimate of 1576 ÷ 21? (a) 7900 (b) 790 (c) 79
  37. 37.Best estimate of 3615 ÷ 56? (a) 600 (b) 60 (c) 6000
  38. 38.Best estimate of 3769 ÷ 44? (a) 94 (b) 9400 (c) 940
  39. 39.√58 to 1 decimal place? (a) 7.5 (b) 7.4 (c) 7.6 (d) 7.7
  40. 40.Best estimate of 752 ÷ 29? (a) 25 (b) 2500 (c) 250

Answer key

  1. 82
  2. 4.8
  3. 9.9
  4. 93
  5. 6.3
  6. 71
  7. 14
  8. 80
  9. 38
  10. 8.6
  11. 23
  12. 20
  13. 7.1
  14. 92
  15. 99
  16. 76
  17. 42
  18. 7.7
  19. 96
  20. 95
  21. 7.4
  22. 30
  23. 67
  24. 8.7
  25. 19
  26. 71
  27. 38
  28. 9.4
  29. 60
  30. 62
  31. 5.6
  32. 48
  33. 16
  34. 8.2
  35. 35
  36. 79
  37. 60
  38. 94
  39. 7.6
  40. 25

Free mental maths lessons, practice and worksheets at talentjr.in/mental-maths