← Estimate divisions and square roots lesson New set →

Estimating Square Roots and Division Worksheet

Mental maths lesson 27: Estimate divisions and square roots · Set 196 · 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.√53 to 1 decimal place? (a) 7.5 (b) 7.3 (c) 7.6 (d) 7.4
  2. 2.√31 to 1 decimal place? (a) 5.7 (b) 5.5 (c) 5.8 (d) 5.6
  3. 3.Best estimate of 477 ÷ 22? (a) 2400 (b) 24 (c) 240
  4. 4.√44 to 1 decimal place? (a) 6.5 (b) 6.7 (c) 6.4 (d) 6.6
  5. 5.√92 to 1 decimal place? (a) 9.7 (b) 9.6 (c) 9.8 (d) 9.5
  6. 6.Best estimate of 2272 ÷ 27? (a) 760 (b) 7600 (c) 76
  7. 7.Best estimate of 2135 ÷ 79? (a) 2700 (b) 270 (c) 27
  8. 8.√84 to 1 decimal place? (a) 9.1 (b) 9.2 (c) 9.3 (d) 9.4
  9. 9.Best estimate of 1969 ÷ 32? (a) 660 (b) 6600 (c) 66
  10. 10.√78 to 1 decimal place? (a) 8.6 (b) 8.8 (c) 8.5 (d) 8.7
  11. 11.Best estimate of 2911 ÷ 34? (a) 970 (b) 97 (c) 9700
  12. 12.Best estimate of 718 ÷ 34? (a) 240 (b) 2400 (c) 24
  13. 13.√82 to 1 decimal place? (a) 8.9 (b) 9.0 (c) 9.1 (d) 8.8
  14. 14.√87 to 1 decimal place? (a) 9.3 (b) 9.0 (c) 9.1 (d) 9.2
  15. 15.√48 to 1 decimal place? (a) 7.2 (b) 6.9 (c) 7.1 (d) 7.0
  16. 16.Best estimate of 5288 ÷ 61? (a) 88 (b) 880 (c) 8800
  17. 17.√58 to 1 decimal place? (a) 7.6 (b) 7.7 (c) 7.8 (d) 7.5
  18. 18.√65 to 1 decimal place? (a) 8.0 (b) 8.1 (c) 7.9 (d) 8.2
  19. 19.Best estimate of 1607 ÷ 86? (a) 18 (b) 180 (c) 1800
  20. 20.Best estimate of 2436 ÷ 32? (a) 81 (b) 8100 (c) 810
  21. 21.Best estimate of 1413 ÷ 56? (a) 240 (b) 2400 (c) 24
  22. 22.Best estimate of 449 ÷ 23? (a) 220 (b) 2200 (c) 22
  23. 23.Best estimate of 4128 ÷ 83? (a) 5200 (b) 520 (c) 52
  24. 24.Best estimate of 3168 ÷ 72? (a) 450 (b) 4500 (c) 45
  25. 25.√51 to 1 decimal place? (a) 7.2 (b) 7.1 (c) 7.3 (d) 7.0
  26. 26.√70 to 1 decimal place? (a) 8.2 (b) 8.3 (c) 8.5 (d) 8.4
  27. 27.√62 to 1 decimal place? (a) 8.1 (b) 8.2 (c) 7.9 (d) 8.0
  28. 28.Best estimate of 3305 ÷ 53? (a) 66 (b) 6600 (c) 660
  29. 29.√74 to 1 decimal place? (a) 8.8 (b) 8.6 (c) 8.7 (d) 8.5
  30. 30.Best estimate of 5024 ÷ 72? (a) 72 (b) 720 (c) 7200
  31. 31.√69 to 1 decimal place? (a) 8.5 (b) 8.6 (c) 8.3 (d) 8.4
  32. 32.Best estimate of 2915 ÷ 59? (a) 4900 (b) 490 (c) 49
  33. 33.Best estimate of 1981 ÷ 32? (a) 66 (b) 660 (c) 6600
  34. 34.Best estimate of 1233 ÷ 37? (a) 31 (b) 3100 (c) 310
  35. 35.Best estimate of 570 ÷ 38? (a) 140 (b) 1400 (c) 14
  36. 36.Best estimate of 1799 ÷ 61? (a) 300 (b) 3000 (c) 30
  37. 37.√43 to 1 decimal place? (a) 6.8 (b) 6.7 (c) 6.6 (d) 6.9
  38. 38.√96 to 1 decimal place? (a) 10.0 (b) 9.8 (c) 9.9 (d) 9.7
  39. 39.Best estimate of 1231 ÷ 37? (a) 3100 (b) 31 (c) 310
  40. 40.Best estimate of 4625 ÷ 67? (a) 66 (b) 660 (c) 6600

Answer key

  1. 7.3
  2. 5.6
  3. 24
  4. 6.6
  5. 9.6
  6. 76
  7. 27
  8. 9.2
  9. 66
  10. 8.8
  11. 97
  12. 24
  13. 9.1
  14. 9.3
  15. 6.9
  16. 88
  17. 7.6
  18. 8.1
  19. 18
  20. 81
  21. 24
  22. 22
  23. 52
  24. 45
  25. 7.1
  26. 8.4
  27. 7.9
  28. 66
  29. 8.6
  30. 72
  31. 8.3
  32. 49
  33. 66
  34. 31
  35. 14
  36. 30
  37. 6.6
  38. 9.8
  39. 31
  40. 66

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