← Estimate divisions and square roots lesson New set →

Estimating Square Roots and Division Worksheet

Mental maths lesson 27: Estimate divisions and square roots · Set 702 · 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.√78 to 1 decimal place? (a) 8.8 (b) 8.5 (c) 8.7 (d) 8.6
  2. 2.Best estimate of 4158 ÷ 62? (a) 690 (b) 69 (c) 6900
  3. 3.√55 to 1 decimal place? (a) 7.2 (b) 7.4 (c) 7.3 (d) 7.5
  4. 4.√75 to 1 decimal place? (a) 8.7 (b) 8.6 (c) 8.5 (d) 8.8
  5. 5.Best estimate of 2003 ÷ 29? (a) 6700 (b) 67 (c) 670
  6. 6.√58 to 1 decimal place? (a) 7.7 (b) 7.9 (c) 7.8 (d) 7.6
  7. 7.√88 to 1 decimal place? (a) 9.4 (b) 9.3 (c) 9.6 (d) 9.5
  8. 8.Best estimate of 3412 ÷ 43? (a) 85 (b) 8500 (c) 850
  9. 9.Best estimate of 3714 ÷ 48? (a) 740 (b) 74 (c) 7400
  10. 10.√66 to 1 decimal place? (a) 8.2 (b) 8.0 (c) 7.9 (d) 8.1
  11. 11.√26 to 1 decimal place? (a) 5.1 (b) 4.8 (c) 5.0 (d) 4.9
  12. 12.√32 to 1 decimal place? (a) 5.7 (b) 5.9 (c) 6.0 (d) 5.8
  13. 13.Best estimate of 1888 ÷ 76? (a) 2400 (b) 24 (c) 240
  14. 14.Best estimate of 1895 ÷ 21? (a) 950 (b) 9500 (c) 95
  15. 15.Best estimate of 3086 ÷ 67? (a) 4400 (b) 440 (c) 44
  16. 16.√43 to 1 decimal place? (a) 6.6 (b) 6.8 (c) 6.5 (d) 6.7
  17. 17.Best estimate of 2832 ÷ 89? (a) 31 (b) 310 (c) 3100
  18. 18.√76 to 1 decimal place? (a) 8.4 (b) 8.5 (c) 8.6 (d) 8.7
  19. 19.√21 to 1 decimal place? (a) 4.5 (b) 4.7 (c) 4.8 (d) 4.6
  20. 20.Best estimate of 1315 ÷ 44? (a) 330 (b) 33 (c) 3300
  21. 21.Best estimate of 505 ÷ 27? (a) 170 (b) 17 (c) 1700
  22. 22.Best estimate of 2113 ÷ 31? (a) 70 (b) 7000 (c) 700
  23. 23.√94 to 1 decimal place? (a) 9.6 (b) 9.9 (c) 9.7 (d) 9.8
  24. 24.Best estimate of 2282 ÷ 72? (a) 33 (b) 3300 (c) 330
  25. 25.√96 to 1 decimal place? (a) 10.1 (b) 10.0 (c) 9.9 (d) 9.8
  26. 26.Best estimate of 3950 ÷ 56? (a) 6600 (b) 660 (c) 66
  27. 27.Best estimate of 2988 ÷ 66? (a) 43 (b) 4300 (c) 430
  28. 28.Best estimate of 1402 ÷ 32? (a) 470 (b) 4700 (c) 47
  29. 29.Best estimate of 384 ÷ 26? (a) 13 (b) 1300 (c) 130
  30. 30.Best estimate of 4782 ÷ 62? (a) 80 (b) 8000 (c) 800
  31. 31.√90 to 1 decimal place? (a) 9.4 (b) 9.3 (c) 9.6 (d) 9.5
  32. 32.Best estimate of 1989 ÷ 32? (a) 660 (b) 66 (c) 6600
  33. 33.√89 to 1 decimal place? (a) 9.5 (b) 9.7 (c) 9.4 (d) 9.6
  34. 34.Best estimate of 3877 ÷ 57? (a) 650 (b) 65 (c) 6500
  35. 35.√27 to 1 decimal place? (a) 5.4 (b) 5.2 (c) 5.3 (d) 5.5
  36. 36.√22 to 1 decimal place? (a) 4.7 (b) 4.9 (c) 4.8 (d) 4.6
  37. 37.√34 to 1 decimal place? (a) 5.8 (b) 5.9 (c) 5.6 (d) 5.7
  38. 38.Best estimate of 5052 ÷ 83? (a) 630 (b) 6300 (c) 63
  39. 39.Best estimate of 6010 ÷ 76? (a) 7500 (b) 75 (c) 750
  40. 40.Best estimate of 2393 ÷ 66? (a) 340 (b) 34 (c) 3400

Answer key

  1. 8.8
  2. 69
  3. 7.4
  4. 8.7
  5. 67
  6. 7.6
  7. 9.4
  8. 85
  9. 74
  10. 8.1
  11. 5.1
  12. 5.7
  13. 24
  14. 95
  15. 44
  16. 6.6
  17. 31
  18. 8.7
  19. 4.6
  20. 33
  21. 17
  22. 70
  23. 9.7
  24. 33
  25. 9.8
  26. 66
  27. 43
  28. 47
  29. 13
  30. 80
  31. 9.5
  32. 66
  33. 9.4
  34. 65
  35. 5.2
  36. 4.7
  37. 5.8
  38. 63
  39. 75
  40. 34

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