← Estimate divisions and square roots lesson New set →

Estimating Square Roots and Division Worksheet

Mental maths lesson 27: Estimate divisions and square roots · Set 54 · 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 800 ÷ 23? (a) 400 (b) 40 (c) 4000
  2. 2.√72 to 1 decimal place? (a) 8.2 (b) 8.5 (c) 8.4 (d) 8.3
  3. 3.Best estimate of 2430 ÷ 38? (a) 610 (b) 6100 (c) 61
  4. 4.√70 to 1 decimal place? (a) 8.4 (b) 8.2 (c) 8.5 (d) 8.3
  5. 5.Best estimate of 3249 ÷ 68? (a) 4600 (b) 460 (c) 46
  6. 6.Best estimate of 479 ÷ 36? (a) 1200 (b) 120 (c) 12
  7. 7.Best estimate of 2436 ÷ 86? (a) 270 (b) 27 (c) 2700
  8. 8.√51 to 1 decimal place? (a) 7.1 (b) 7.0 (c) 6.9 (d) 7.2
  9. 9.Best estimate of 4444 ÷ 67? (a) 63 (b) 6300 (c) 630
  10. 10.√55 to 1 decimal place? (a) 7.7 (b) 7.4 (c) 7.5 (d) 7.6
  11. 11.√63 to 1 decimal place? (a) 7.7 (b) 7.8 (c) 7.9 (d) 7.6
  12. 12.√44 to 1 decimal place? (a) 6.6 (b) 6.8 (c) 6.5 (d) 6.7
  13. 13.Best estimate of 1721 ÷ 54? (a) 340 (b) 34 (c) 3400
  14. 14.√82 to 1 decimal place? (a) 9.2 (b) 8.9 (c) 9.1 (d) 9.0
  15. 15.√28 to 1 decimal place? (a) 5.2 (b) 5.5 (c) 5.4 (d) 5.3
  16. 16.√31 to 1 decimal place? (a) 5.8 (b) 5.7 (c) 5.9 (d) 5.6
  17. 17.√37 to 1 decimal place? (a) 6.1 (b) 5.9 (c) 6.2 (d) 6.0
  18. 18.Best estimate of 496 ÷ 26? (a) 170 (b) 1700 (c) 17
  19. 19.√87 to 1 decimal place? (a) 9.2 (b) 9.4 (c) 9.3 (d) 9.5
  20. 20.Best estimate of 2975 ÷ 86? (a) 3300 (b) 330 (c) 33
  21. 21.√50 to 1 decimal place? (a) 7.1 (b) 7.2 (c) 6.9 (d) 7.0
  22. 22.Best estimate of 3788 ÷ 79? (a) 4700 (b) 47 (c) 470
  23. 23.√24 to 1 decimal place? (a) 5.2 (b) 4.9 (c) 5.1 (d) 5.0
  24. 24.Best estimate of 5150 ÷ 62? (a) 860 (b) 8600 (c) 86
  25. 25.√27 to 1 decimal place? (a) 4.9 (b) 5.2 (c) 5.0 (d) 5.1
  26. 26.√40 to 1 decimal place? (a) 6.2 (b) 6.1 (c) 6.4 (d) 6.3
  27. 27.Best estimate of 1113 ÷ 33? (a) 370 (b) 37 (c) 3700
  28. 28.Best estimate of 2433 ÷ 26? (a) 81 (b) 8100 (c) 810
  29. 29.Best estimate of 2085 ÷ 71? (a) 3000 (b) 30 (c) 300
  30. 30.Best estimate of 2235 ÷ 42? (a) 5600 (b) 56 (c) 560
  31. 31.√86 to 1 decimal place? (a) 9.4 (b) 9.5 (c) 9.6 (d) 9.3
  32. 32.Best estimate of 2286 ÷ 68? (a) 3300 (b) 33 (c) 330
  33. 33.Best estimate of 1744 ÷ 54? (a) 3500 (b) 350 (c) 35
  34. 34.Best estimate of 4299 ÷ 46? (a) 8600 (b) 86 (c) 860
  35. 35.Best estimate of 2667 ÷ 82? (a) 3300 (b) 330 (c) 33
  36. 36.Best estimate of 1035 ÷ 48? (a) 210 (b) 2100 (c) 21
  37. 37.Best estimate of 1194 ÷ 67? (a) 170 (b) 17 (c) 1700
  38. 38.Best estimate of 2191 ÷ 53? (a) 440 (b) 4400 (c) 44
  39. 39.Best estimate of 3638 ÷ 46? (a) 7300 (b) 73 (c) 730
  40. 40.√38 to 1 decimal place? (a) 6.4 (b) 6.3 (c) 6.2 (d) 6.5

Answer key

  1. 40
  2. 8.5
  3. 61
  4. 8.4
  5. 46
  6. 12
  7. 27
  8. 7.1
  9. 63
  10. 7.4
  11. 7.9
  12. 6.6
  13. 34
  14. 9.1
  15. 5.3
  16. 5.6
  17. 6.1
  18. 17
  19. 9.3
  20. 33
  21. 7.1
  22. 47
  23. 4.9
  24. 86
  25. 5.2
  26. 6.3
  27. 37
  28. 81
  29. 30
  30. 56
  31. 9.3
  32. 33
  33. 35
  34. 86
  35. 33
  36. 21
  37. 17
  38. 44
  39. 73
  40. 6.2

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