← Estimate divisions and square roots lesson New set →

Estimating Square Roots and Division Worksheet

Mental maths lesson 27: Estimate divisions and square roots · Set 263 · 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 3634 ÷ 47? (a) 73 (b) 730 (c) 7300
  2. 2.√72 to 1 decimal place? (a) 8.7 (b) 8.6 (c) 8.8 (d) 8.5
  3. 3.√62 to 1 decimal place? (a) 7.9 (b) 7.8 (c) 8.0 (d) 7.7
  4. 4.√74 to 1 decimal place? (a) 8.9 (b) 8.6 (c) 8.8 (d) 8.7
  5. 5.√30 to 1 decimal place? (a) 5.2 (b) 5.4 (c) 5.5 (d) 5.3
  6. 6.√50 to 1 decimal place? (a) 7.4 (b) 7.1 (c) 7.2 (d) 7.3
  7. 7.Best estimate of 1602 ÷ 64? (a) 270 (b) 2700 (c) 27
  8. 8.√26 to 1 decimal place? (a) 5.3 (b) 5.1 (c) 5.2 (d) 5.0
  9. 9.√58 to 1 decimal place? (a) 7.5 (b) 7.4 (c) 7.6 (d) 7.3
  10. 10.Best estimate of 584 ÷ 31? (a) 19 (b) 190 (c) 1900
  11. 11.√87 to 1 decimal place? (a) 9.2 (b) 9.4 (c) 9.5 (d) 9.3
  12. 12.Best estimate of 5642 ÷ 72? (a) 810 (b) 81 (c) 8100
  13. 13.√94 to 1 decimal place? (a) 9.6 (b) 9.4 (c) 9.5 (d) 9.7
  14. 14.√75 to 1 decimal place? (a) 8.9 (b) 8.8 (c) 9.0 (d) 8.7
  15. 15.Best estimate of 1938 ÷ 46? (a) 390 (b) 3900 (c) 39
  16. 16.Best estimate of 3918 ÷ 43? (a) 980 (b) 9800 (c) 98
  17. 17.Best estimate of 1883 ÷ 37? (a) 47 (b) 470 (c) 4700
  18. 18.√43 to 1 decimal place? (a) 6.7 (b) 6.4 (c) 6.5 (d) 6.6
  19. 19.√29 to 1 decimal place? (a) 5.2 (b) 5.3 (c) 5.1 (d) 5.4
  20. 20.√67 to 1 decimal place? (a) 8.2 (b) 8.5 (c) 8.4 (d) 8.3
  21. 21.Best estimate of 2387 ÷ 72? (a) 340 (b) 3400 (c) 34
  22. 22.√61 to 1 decimal place? (a) 7.7 (b) 7.5 (c) 7.8 (d) 7.6
  23. 23.√20 to 1 decimal place? (a) 4.6 (b) 4.7 (c) 4.5 (d) 4.4
  24. 24.√24 to 1 decimal place? (a) 4.7 (b) 4.9 (c) 4.6 (d) 4.8
  25. 25.√69 to 1 decimal place? (a) 8.5 (b) 8.6 (c) 8.4 (d) 8.3
  26. 26.Best estimate of 3686 ÷ 42? (a) 9200 (b) 92 (c) 920
  27. 27.Best estimate of 931 ÷ 34? (a) 3100 (b) 310 (c) 31
  28. 28.Best estimate of 2283 ÷ 54? (a) 46 (b) 4600 (c) 460
  29. 29.√84 to 1 decimal place? (a) 9.4 (b) 9.5 (c) 9.2 (d) 9.3
  30. 30.Best estimate of 3043 ÷ 37? (a) 7600 (b) 76 (c) 760
  31. 31.Best estimate of 832 ÷ 37? (a) 2100 (b) 21 (c) 210
  32. 32.Best estimate of 6414 ÷ 89? (a) 710 (b) 7100 (c) 71
  33. 33.Best estimate of 665 ÷ 36? (a) 1700 (b) 170 (c) 17
  34. 34.√21 to 1 decimal place? (a) 4.6 (b) 4.7 (c) 4.4 (d) 4.5
  35. 35.√37 to 1 decimal place? (a) 5.9 (b) 6.1 (c) 5.8 (d) 6.0
  36. 36.√55 to 1 decimal place? (a) 7.4 (b) 7.5 (c) 7.2 (d) 7.3
  37. 37.√90 to 1 decimal place? (a) 9.5 (b) 9.6 (c) 9.4 (d) 9.3
  38. 38.Best estimate of 2767 ÷ 86? (a) 310 (b) 3100 (c) 31
  39. 39.Best estimate of 1678 ÷ 39? (a) 420 (b) 4200 (c) 42
  40. 40.Best estimate of 2417 ÷ 78? (a) 3000 (b) 300 (c) 30

Answer key

  1. 73
  2. 8.5
  3. 7.9
  4. 8.6
  5. 5.5
  6. 7.1
  7. 27
  8. 5.1
  9. 7.6
  10. 19
  11. 9.3
  12. 81
  13. 9.7
  14. 8.7
  15. 39
  16. 98
  17. 47
  18. 6.6
  19. 5.4
  20. 8.2
  21. 34
  22. 7.8
  23. 4.5
  24. 4.9
  25. 8.3
  26. 92
  27. 31
  28. 46
  29. 9.2
  30. 76
  31. 21
  32. 71
  33. 17
  34. 4.6
  35. 6.1
  36. 7.4
  37. 9.5
  38. 31
  39. 42
  40. 30

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