← Estimate divisions and square roots lesson New set →

Estimating Square Roots and Division Worksheet

Mental maths lesson 27: Estimate divisions and square roots · Set 19 · 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.√22 to 1 decimal place? (a) 4.9 (b) 4.7 (c) 4.6 (d) 4.8
  2. 2.Best estimate of 3306 ÷ 87? (a) 37 (b) 370 (c) 3700
  3. 3.Best estimate of 1201 ÷ 26? (a) 4000 (b) 40 (c) 400
  4. 4.√38 to 1 decimal place? (a) 6.0 (b) 6.1 (c) 6.3 (d) 6.2
  5. 5.Best estimate of 1006 ÷ 62? (a) 170 (b) 1700 (c) 17
  6. 6.Best estimate of 3171 ÷ 79? (a) 4000 (b) 40 (c) 400
  7. 7.Best estimate of 3619 ÷ 86? (a) 400 (b) 40 (c) 4000
  8. 8.Best estimate of 1743 ÷ 56? (a) 29 (b) 290 (c) 2900
  9. 9.Best estimate of 1500 ÷ 37? (a) 380 (b) 3800 (c) 38
  10. 10.Best estimate of 2054 ÷ 44? (a) 510 (b) 5100 (c) 51
  11. 11.Best estimate of 5900 ÷ 73? (a) 84 (b) 840 (c) 8400
  12. 12.Best estimate of 2187 ÷ 23? (a) 1090 (b) 109 (c) 10900
  13. 13.√40 to 1 decimal place? (a) 6.5 (b) 6.3 (c) 6.2 (d) 6.4
  14. 14.Best estimate of 2316 ÷ 33? (a) 770 (b) 7700 (c) 77
  15. 15.√35 to 1 decimal place? (a) 5.7 (b) 5.8 (c) 5.6 (d) 5.9
  16. 16.√67 to 1 decimal place? (a) 8.2 (b) 8.3 (c) 8.0 (d) 8.1
  17. 17.√71 to 1 decimal place? (a) 8.7 (b) 8.5 (c) 8.6 (d) 8.4
  18. 18.√82 to 1 decimal place? (a) 9.2 (b) 9.4 (c) 9.3 (d) 9.1
  19. 19.√27 to 1 decimal place? (a) 5.1 (b) 5.2 (c) 5.0 (d) 4.9
  20. 20.√98 to 1 decimal place? (a) 10.1 (b) 10.0 (c) 9.8 (d) 9.9
  21. 21.√70 to 1 decimal place? (a) 8.2 (b) 8.3 (c) 8.4 (d) 8.1
  22. 22.√94 to 1 decimal place? (a) 9.8 (b) 10.0 (c) 9.7 (d) 9.9
  23. 23.√47 to 1 decimal place? (a) 6.7 (b) 7.0 (c) 6.9 (d) 6.8
  24. 24.Best estimate of 1560 ÷ 72? (a) 22 (b) 2200 (c) 220
  25. 25.Best estimate of 5488 ÷ 77? (a) 6900 (b) 69 (c) 690
  26. 26.√92 to 1 decimal place? (a) 9.6 (b) 9.4 (c) 9.5 (d) 9.3
  27. 27.√66 to 1 decimal place? (a) 7.8 (b) 7.9 (c) 8.0 (d) 8.1
  28. 28.Best estimate of 2032 ÷ 42? (a) 510 (b) 51 (c) 5100
  29. 29.√96 to 1 decimal place? (a) 9.7 (b) 9.9 (c) 9.6 (d) 9.8
  30. 30.√50 to 1 decimal place? (a) 7.1 (b) 7.3 (c) 7.4 (d) 7.2
  31. 31.√32 to 1 decimal place? (a) 5.6 (b) 5.5 (c) 5.7 (d) 5.4
  32. 32.√28 to 1 decimal place? (a) 5.2 (b) 5.1 (c) 5.3 (d) 5.0
  33. 33.Best estimate of 1696 ÷ 86? (a) 190 (b) 1900 (c) 19
  34. 34.Best estimate of 4960 ÷ 73? (a) 7100 (b) 71 (c) 710
  35. 35.Best estimate of 6968 ÷ 76? (a) 8700 (b) 87 (c) 870
  36. 36.Best estimate of 3335 ÷ 56? (a) 560 (b) 5600 (c) 56
  37. 37.√30 to 1 decimal place? (a) 5.8 (b) 5.6 (c) 5.7 (d) 5.5
  38. 38.√74 to 1 decimal place? (a) 8.5 (b) 8.6 (c) 8.7 (d) 8.4
  39. 39.√72 to 1 decimal place? (a) 8.3 (b) 8.5 (c) 8.2 (d) 8.4
  40. 40.√26 to 1 decimal place? (a) 5.4 (b) 5.1 (c) 5.3 (d) 5.2

Answer key

  1. 4.7
  2. 37
  3. 40
  4. 6.2
  5. 17
  6. 40
  7. 40
  8. 29
  9. 38
  10. 51
  11. 84
  12. 109
  13. 6.3
  14. 77
  15. 5.9
  16. 8.2
  17. 8.4
  18. 9.1
  19. 5.2
  20. 9.9
  21. 8.4
  22. 9.7
  23. 6.9
  24. 22
  25. 69
  26. 9.6
  27. 8.1
  28. 51
  29. 9.8
  30. 7.1
  31. 5.7
  32. 5.3
  33. 19
  34. 71
  35. 87
  36. 56
  37. 5.5
  38. 8.6
  39. 8.5
  40. 5.1

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