← Estimate divisions and square roots lesson New set →

Estimating Square Roots and Division Worksheet

Mental maths lesson 27: Estimate divisions and square roots · Set 877 · 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 2832 ÷ 61? (a) 470 (b) 47 (c) 4700
  2. 2.√92 to 1 decimal place? (a) 9.5 (b) 9.6 (c) 9.4 (d) 9.3
  3. 3.√46 to 1 decimal place? (a) 7.0 (b) 7.1 (c) 6.9 (d) 6.8
  4. 4.√40 to 1 decimal place? (a) 6.2 (b) 6.3 (c) 6.5 (d) 6.4
  5. 5.Best estimate of 3917 ÷ 56? (a) 65 (b) 650 (c) 6500
  6. 6.√31 to 1 decimal place? (a) 5.6 (b) 5.3 (c) 5.5 (d) 5.4
  7. 7.Best estimate of 2954 ÷ 59? (a) 4900 (b) 49 (c) 490
  8. 8.√65 to 1 decimal place? (a) 8.0 (b) 8.1 (c) 7.9 (d) 8.2
  9. 9.√24 to 1 decimal place? (a) 4.8 (b) 4.9 (c) 4.7 (d) 5.0
  10. 10.Best estimate of 2592 ÷ 29? (a) 8600 (b) 86 (c) 860
  11. 11.√53 to 1 decimal place? (a) 7.6 (b) 7.4 (c) 7.5 (d) 7.3
  12. 12.√47 to 1 decimal place? (a) 7.2 (b) 7.0 (c) 7.1 (d) 6.9
  13. 13.Best estimate of 1848 ÷ 84? (a) 230 (b) 2300 (c) 23
  14. 14.Best estimate of 992 ÷ 37? (a) 250 (b) 2500 (c) 25
  15. 15.Best estimate of 6610 ÷ 76? (a) 83 (b) 8300 (c) 830
  16. 16.Best estimate of 2757 ÷ 53? (a) 550 (b) 55 (c) 5500
  17. 17.Best estimate of 3138 ÷ 66? (a) 4500 (b) 450 (c) 45
  18. 18.Best estimate of 5051 ÷ 62? (a) 840 (b) 84 (c) 8400
  19. 19.√21 to 1 decimal place? (a) 4.8 (b) 4.6 (c) 4.5 (d) 4.7
  20. 20.√38 to 1 decimal place? (a) 6.3 (b) 6.1 (c) 6.2 (d) 6.0
  21. 21.Best estimate of 1219 ÷ 42? (a) 300 (b) 3000 (c) 30
  22. 22.Best estimate of 4482 ÷ 54? (a) 900 (b) 9000 (c) 90
  23. 23.Best estimate of 1295 ÷ 83? (a) 1600 (b) 16 (c) 160
  24. 24.Best estimate of 1727 ÷ 62? (a) 290 (b) 2900 (c) 29
  25. 25.√22 to 1 decimal place? (a) 4.8 (b) 4.9 (c) 4.6 (d) 4.7
  26. 26.Best estimate of 5341 ÷ 76? (a) 6700 (b) 67 (c) 670
  27. 27.Best estimate of 4721 ÷ 57? (a) 79 (b) 7900 (c) 790
  28. 28.Best estimate of 2408 ÷ 53? (a) 48 (b) 4800 (c) 480
  29. 29.√74 to 1 decimal place? (a) 8.4 (b) 8.3 (c) 8.5 (d) 8.6
  30. 30.√35 to 1 decimal place? (a) 5.9 (b) 5.7 (c) 5.8 (d) 6.0
  31. 31.Best estimate of 842 ÷ 29? (a) 28 (b) 280 (c) 2800
  32. 32.Best estimate of 1468 ÷ 72? (a) 210 (b) 2100 (c) 21
  33. 33.Best estimate of 3234 ÷ 52? (a) 6500 (b) 65 (c) 650
  34. 34.Best estimate of 2557 ÷ 36? (a) 64 (b) 640 (c) 6400
  35. 35.Best estimate of 5830 ÷ 64? (a) 97 (b) 9700 (c) 970
  36. 36.Best estimate of 6606 ÷ 84? (a) 8300 (b) 830 (c) 83
  37. 37.Best estimate of 2349 ÷ 46? (a) 47 (b) 470 (c) 4700
  38. 38.√62 to 1 decimal place? (a) 8.0 (b) 7.8 (c) 8.1 (d) 7.9
  39. 39.Best estimate of 4415 ÷ 56? (a) 7400 (b) 74 (c) 740
  40. 40.Best estimate of 5258 ÷ 82? (a) 6600 (b) 660 (c) 66

Answer key

  1. 47
  2. 9.6
  3. 6.8
  4. 6.3
  5. 65
  6. 5.6
  7. 49
  8. 8.1
  9. 4.9
  10. 86
  11. 7.3
  12. 6.9
  13. 23
  14. 25
  15. 83
  16. 55
  17. 45
  18. 84
  19. 4.6
  20. 6.2
  21. 30
  22. 90
  23. 16
  24. 29
  25. 4.7
  26. 67
  27. 79
  28. 48
  29. 8.6
  30. 5.9
  31. 28
  32. 21
  33. 65
  34. 64
  35. 97
  36. 83
  37. 47
  38. 7.9
  39. 74
  40. 66

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