← Estimate divisions and square roots lesson New set →

Estimating Square Roots and Division Worksheet

Mental maths lesson 27: Estimate divisions and square roots · Set 740 · 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.√96 to 1 decimal place? (a) 9.7 (b) 9.6 (c) 9.8 (d) 9.5
  2. 2.√72 to 1 decimal place? (a) 8.7 (b) 8.6 (c) 8.8 (d) 8.5
  3. 3.√34 to 1 decimal place? (a) 5.9 (b) 5.6 (c) 5.7 (d) 5.8
  4. 4.Best estimate of 1295 ÷ 32? (a) 43 (b) 430 (c) 4300
  5. 5.√50 to 1 decimal place? (a) 7.1 (b) 7.0 (c) 6.9 (d) 6.8
  6. 6.√45 to 1 decimal place? (a) 6.5 (b) 6.7 (c) 6.6 (d) 6.4
  7. 7.Best estimate of 2557 ÷ 27? (a) 85 (b) 8500 (c) 850
  8. 8.Best estimate of 2626 ÷ 72? (a) 3800 (b) 380 (c) 38
  9. 9.Best estimate of 4753 ÷ 64? (a) 790 (b) 79 (c) 7900
  10. 10.√70 to 1 decimal place? (a) 8.5 (b) 8.6 (c) 8.7 (d) 8.4
  11. 11.√41 to 1 decimal place? (a) 6.4 (b) 6.2 (c) 6.3 (d) 6.1
  12. 12.√92 to 1 decimal place? (a) 9.4 (b) 9.5 (c) 9.7 (d) 9.6
  13. 13.Best estimate of 5755 ÷ 66? (a) 820 (b) 8200 (c) 82
  14. 14.Best estimate of 3156 ÷ 54? (a) 630 (b) 6300 (c) 63
  15. 15.√94 to 1 decimal place? (a) 9.6 (b) 9.7 (c) 9.9 (d) 9.8
  16. 16.√98 to 1 decimal place? (a) 9.8 (b) 10.0 (c) 9.7 (d) 9.9
  17. 17.√55 to 1 decimal place? (a) 7.3 (b) 7.2 (c) 7.4 (d) 7.5
  18. 18.√89 to 1 decimal place? (a) 9.4 (b) 9.6 (c) 9.5 (d) 9.7
  19. 19.Best estimate of 1242 ÷ 36? (a) 3100 (b) 310 (c) 31
  20. 20.√40 to 1 decimal place? (a) 6.3 (b) 6.4 (c) 6.6 (d) 6.5
  21. 21.Best estimate of 4860 ÷ 58? (a) 8100 (b) 81 (c) 810
  22. 22.√87 to 1 decimal place? (a) 9.4 (b) 9.5 (c) 9.3 (d) 9.6
  23. 23.√28 to 1 decimal place? (a) 5.5 (b) 5.6 (c) 5.4 (d) 5.3
  24. 24.Best estimate of 3169 ÷ 34? (a) 106 (b) 10600 (c) 1060
  25. 25.Best estimate of 2495 ÷ 76? (a) 3100 (b) 310 (c) 31
  26. 26.√67 to 1 decimal place? (a) 7.9 (b) 8.1 (c) 8.0 (d) 8.2
  27. 27.√24 to 1 decimal place? (a) 5.1 (b) 4.8 (c) 4.9 (d) 5.0
  28. 28.√69 to 1 decimal place? (a) 8.4 (b) 8.1 (c) 8.2 (d) 8.3
  29. 29.Best estimate of 1270 ÷ 72? (a) 180 (b) 1800 (c) 18
  30. 30.Best estimate of 2147 ÷ 34? (a) 7200 (b) 720 (c) 72
  31. 31.Best estimate of 3626 ÷ 46? (a) 7300 (b) 730 (c) 73
  32. 32.√43 to 1 decimal place? (a) 6.7 (b) 6.5 (c) 6.8 (d) 6.6
  33. 33.Best estimate of 6531 ÷ 86? (a) 7300 (b) 73 (c) 730
  34. 34.√29 to 1 decimal place? (a) 5.4 (b) 5.6 (c) 5.7 (d) 5.5
  35. 35.Best estimate of 1699 ÷ 36? (a) 4200 (b) 420 (c) 42
  36. 36.√53 to 1 decimal place? (a) 7.4 (b) 7.6 (c) 7.3 (d) 7.5
  37. 37.Best estimate of 2312 ÷ 61? (a) 390 (b) 3900 (c) 39
  38. 38.√62 to 1 decimal place? (a) 7.9 (b) 8.0 (c) 8.1 (d) 8.2
  39. 39.√66 to 1 decimal place? (a) 8.1 (b) 8.2 (c) 8.3 (d) 8.4
  40. 40.√48 to 1 decimal place? (a) 6.9 (b) 7.2 (c) 7.0 (d) 7.1

Answer key

  1. 9.8
  2. 8.5
  3. 5.8
  4. 43
  5. 7.1
  6. 6.7
  7. 85
  8. 38
  9. 79
  10. 8.4
  11. 6.4
  12. 9.6
  13. 82
  14. 63
  15. 9.7
  16. 9.9
  17. 7.4
  18. 9.4
  19. 31
  20. 6.3
  21. 81
  22. 9.3
  23. 5.3
  24. 106
  25. 31
  26. 8.2
  27. 4.9
  28. 8.3
  29. 18
  30. 72
  31. 73
  32. 6.6
  33. 73
  34. 5.4
  35. 42
  36. 7.3
  37. 39
  38. 7.9
  39. 8.1
  40. 6.9

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