← Estimate divisions and square roots lesson New set →

Estimating Square Roots and Division Worksheet

Mental maths lesson 27: Estimate divisions and square roots · Set 189 · 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 3504 ÷ 42? (a) 880 (b) 88 (c) 8800
  2. 2.√32 to 1 decimal place? (a) 6.0 (b) 5.9 (c) 5.7 (d) 5.8
  3. 3.√83 to 1 decimal place? (a) 9.2 (b) 9.0 (c) 9.1 (d) 9.3
  4. 4.Best estimate of 4568 ÷ 63? (a) 7600 (b) 760 (c) 76
  5. 5.√59 to 1 decimal place? (a) 7.7 (b) 7.5 (c) 7.6 (d) 7.4
  6. 6.Best estimate of 4807 ÷ 86? (a) 530 (b) 5300 (c) 53
  7. 7.√40 to 1 decimal place? (a) 6.2 (b) 6.1 (c) 6.0 (d) 6.3
  8. 8.√86 to 1 decimal place? (a) 9.6 (b) 9.5 (c) 9.3 (d) 9.4
  9. 9.Best estimate of 2617 ÷ 57? (a) 440 (b) 4400 (c) 44
  10. 10.Best estimate of 635 ÷ 34? (a) 21 (b) 210 (c) 2100
  11. 11.√30 to 1 decimal place? (a) 5.6 (b) 5.5 (c) 5.4 (d) 5.3
  12. 12.Best estimate of 3818 ÷ 68? (a) 550 (b) 5500 (c) 55
  13. 13.√88 to 1 decimal place? (a) 9.6 (b) 9.4 (c) 9.5 (d) 9.7
  14. 14.Best estimate of 590 ÷ 38? (a) 15 (b) 1500 (c) 150
  15. 15.Best estimate of 2357 ÷ 47? (a) 470 (b) 4700 (c) 47
  16. 16.Best estimate of 3851 ÷ 68? (a) 5500 (b) 55 (c) 550
  17. 17.Best estimate of 1377 ÷ 72? (a) 200 (b) 2000 (c) 20
  18. 18.Best estimate of 2474 ÷ 76? (a) 31 (b) 310 (c) 3100
  19. 19.Best estimate of 3798 ÷ 76? (a) 47 (b) 4700 (c) 470
  20. 20.√85 to 1 decimal place? (a) 9.0 (b) 9.3 (c) 9.2 (d) 9.1
  21. 21.Best estimate of 4748 ÷ 66? (a) 6800 (b) 68 (c) 680
  22. 22.Best estimate of 1837 ÷ 66? (a) 2600 (b) 26 (c) 260
  23. 23.Best estimate of 4052 ÷ 52? (a) 8100 (b) 810 (c) 81
  24. 24.Best estimate of 6031 ÷ 63? (a) 1010 (b) 101 (c) 10100
  25. 25.√94 to 1 decimal place? (a) 9.7 (b) 9.4 (c) 9.6 (d) 9.5
  26. 26.Best estimate of 3075 ÷ 72? (a) 4400 (b) 44 (c) 440
  27. 27.√65 to 1 decimal place? (a) 8.4 (b) 8.1 (c) 8.2 (d) 8.3
  28. 28.√61 to 1 decimal place? (a) 7.8 (b) 7.6 (c) 7.9 (d) 7.7
  29. 29.Best estimate of 2382 ÷ 32? (a) 79 (b) 7900 (c) 790
  30. 30.Best estimate of 1067 ÷ 51? (a) 210 (b) 2100 (c) 21
  31. 31.Best estimate of 1883 ÷ 53? (a) 380 (b) 3800 (c) 38
  32. 32.√22 to 1 decimal place? (a) 4.5 (b) 4.7 (c) 4.4 (d) 4.6
  33. 33.Best estimate of 2163 ÷ 44? (a) 540 (b) 54 (c) 5400
  34. 34.√66 to 1 decimal place? (a) 8.3 (b) 8.2 (c) 8.0 (d) 8.1
  35. 35.Best estimate of 5038 ÷ 67? (a) 720 (b) 7200 (c) 72
  36. 36.Best estimate of 1571 ÷ 66? (a) 2200 (b) 220 (c) 22
  37. 37.Best estimate of 1225 ÷ 32? (a) 410 (b) 41 (c) 4100
  38. 38.Best estimate of 349 ÷ 24? (a) 1700 (b) 17 (c) 170
  39. 39.Best estimate of 2196 ÷ 61? (a) 37 (b) 370 (c) 3700
  40. 40.√29 to 1 decimal place? (a) 5.4 (b) 5.3 (c) 5.5 (d) 5.2

Answer key

  1. 88
  2. 5.7
  3. 9.1
  4. 76
  5. 7.7
  6. 53
  7. 6.3
  8. 9.3
  9. 44
  10. 21
  11. 5.5
  12. 55
  13. 9.4
  14. 15
  15. 47
  16. 55
  17. 20
  18. 31
  19. 47
  20. 9.2
  21. 68
  22. 26
  23. 81
  24. 101
  25. 9.7
  26. 44
  27. 8.1
  28. 7.8
  29. 79
  30. 21
  31. 38
  32. 4.7
  33. 54
  34. 8.1
  35. 72
  36. 22
  37. 41
  38. 17
  39. 37
  40. 5.4

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