← Estimate divisions and square roots lesson New set →

Estimating Square Roots and Division Worksheet

Mental maths lesson 27: Estimate divisions and square roots · Set 636 · 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.√48 to 1 decimal place? (a) 7.0 (b) 7.1 (c) 7.2 (d) 6.9
  2. 2.√26 to 1 decimal place? (a) 5.1 (b) 5.2 (c) 5.0 (d) 5.3
  3. 3.√43 to 1 decimal place? (a) 6.5 (b) 6.4 (c) 6.7 (d) 6.6
  4. 4.√94 to 1 decimal place? (a) 9.9 (b) 9.7 (c) 9.8 (d) 10.0
  5. 5.√37 to 1 decimal place? (a) 6.4 (b) 6.2 (c) 6.1 (d) 6.3
  6. 6.Best estimate of 892 ÷ 22? (a) 4500 (b) 45 (c) 450
  7. 7.√79 to 1 decimal place? (a) 9.2 (b) 9.1 (c) 8.9 (d) 9.0
  8. 8.√89 to 1 decimal place? (a) 9.3 (b) 9.6 (c) 9.5 (d) 9.4
  9. 9.√59 to 1 decimal place? (a) 7.5 (b) 7.7 (c) 7.4 (d) 7.6
  10. 10.Best estimate of 1802 ÷ 26? (a) 6000 (b) 60 (c) 600
  11. 11.Best estimate of 894 ÷ 58? (a) 15 (b) 150 (c) 1500
  12. 12.√34 to 1 decimal place? (a) 5.8 (b) 5.6 (c) 5.5 (d) 5.7
  13. 13.Best estimate of 2668 ÷ 29? (a) 89 (b) 8900 (c) 890
  14. 14.Best estimate of 4030 ÷ 76? (a) 5000 (b) 500 (c) 50
  15. 15.Best estimate of 804 ÷ 29? (a) 270 (b) 2700 (c) 27
  16. 16.Best estimate of 2082 ÷ 31? (a) 6900 (b) 69 (c) 690
  17. 17.Best estimate of 2480 ÷ 37? (a) 6200 (b) 62 (c) 620
  18. 18.Best estimate of 2981 ÷ 83? (a) 3700 (b) 37 (c) 370
  19. 19.√29 to 1 decimal place? (a) 5.2 (b) 5.5 (c) 5.3 (d) 5.4
  20. 20.Best estimate of 1527 ÷ 79? (a) 1900 (b) 190 (c) 19
  21. 21.Best estimate of 3437 ÷ 46? (a) 6900 (b) 69 (c) 690
  22. 22.√77 to 1 decimal place? (a) 8.8 (b) 9.0 (c) 8.9 (d) 8.7
  23. 23.√92 to 1 decimal place? (a) 9.4 (b) 9.5 (c) 9.6 (d) 9.3
  24. 24.Best estimate of 3848 ÷ 81? (a) 4800 (b) 480 (c) 48
  25. 25.√32 to 1 decimal place? (a) 5.5 (b) 5.8 (c) 5.7 (d) 5.6
  26. 26.Best estimate of 3957 ÷ 69? (a) 570 (b) 5700 (c) 57
  27. 27.√58 to 1 decimal place? (a) 7.8 (b) 7.9 (c) 7.7 (d) 7.6
  28. 28.√62 to 1 decimal place? (a) 7.8 (b) 7.7 (c) 7.9 (d) 7.6
  29. 29.Best estimate of 2832 ÷ 42? (a) 7100 (b) 71 (c) 710
  30. 30.Best estimate of 7416 ÷ 88? (a) 8200 (b) 820 (c) 82
  31. 31.Best estimate of 1661 ÷ 26? (a) 55 (b) 5500 (c) 550
  32. 32.√67 to 1 decimal place? (a) 8.2 (b) 8.5 (c) 8.3 (d) 8.4
  33. 33.Best estimate of 2450 ÷ 46? (a) 4900 (b) 49 (c) 490
  34. 34.Best estimate of 3665 ÷ 74? (a) 52 (b) 520 (c) 5200
  35. 35.√47 to 1 decimal place? (a) 6.9 (b) 7.0 (c) 6.8 (d) 7.1
  36. 36.Best estimate of 4273 ÷ 54? (a) 85 (b) 8500 (c) 850
  37. 37.Best estimate of 1136 ÷ 29? (a) 38 (b) 380 (c) 3800
  38. 38.Best estimate of 1468 ÷ 62? (a) 2400 (b) 24 (c) 240
  39. 39.Best estimate of 4044 ÷ 82? (a) 5100 (b) 510 (c) 51
  40. 40.Best estimate of 3743 ÷ 54? (a) 7500 (b) 750 (c) 75

Answer key

  1. 6.9
  2. 5.1
  3. 6.6
  4. 9.7
  5. 6.1
  6. 45
  7. 8.9
  8. 9.4
  9. 7.7
  10. 60
  11. 15
  12. 5.8
  13. 89
  14. 50
  15. 27
  16. 69
  17. 62
  18. 37
  19. 5.4
  20. 19
  21. 69
  22. 8.8
  23. 9.6
  24. 48
  25. 5.7
  26. 57
  27. 7.6
  28. 7.9
  29. 71
  30. 82
  31. 55
  32. 8.2
  33. 49
  34. 52
  35. 6.9
  36. 85
  37. 38
  38. 24
  39. 51
  40. 75

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