← Estimate divisions and square roots lesson New set →

Estimating Square Roots and Division Worksheet

Mental maths lesson 27: Estimate divisions and square roots · Set 323 · 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.√20 to 1 decimal place? (a) 4.4 (b) 4.2 (c) 4.5 (d) 4.3
  2. 2.Best estimate of 4437 ÷ 61? (a) 74 (b) 740 (c) 7400
  3. 3.Best estimate of 1062 ÷ 47? (a) 210 (b) 21 (c) 2100
  4. 4.√82 to 1 decimal place? (a) 9.1 (b) 9.2 (c) 9.3 (d) 9.0
  5. 5.√26 to 1 decimal place? (a) 5.3 (b) 5.4 (c) 5.1 (d) 5.2
  6. 6.√77 to 1 decimal place? (a) 8.7 (b) 8.5 (c) 8.6 (d) 8.8
  7. 7.Best estimate of 1481 ÷ 52? (a) 3000 (b) 30 (c) 300
  8. 8.Best estimate of 4108 ÷ 56? (a) 680 (b) 68 (c) 6800
  9. 9.Best estimate of 3242 ÷ 64? (a) 54 (b) 5400 (c) 540
  10. 10.Best estimate of 3242 ÷ 59? (a) 540 (b) 5400 (c) 54
  11. 11.Best estimate of 1749 ÷ 89? (a) 190 (b) 19 (c) 1900
  12. 12.√69 to 1 decimal place? (a) 8.5 (b) 8.3 (c) 8.4 (d) 8.2
  13. 13.Best estimate of 3300 ÷ 43? (a) 8300 (b) 83 (c) 830
  14. 14.√74 to 1 decimal place? (a) 8.8 (b) 8.5 (c) 8.7 (d) 8.6
  15. 15.Best estimate of 913 ÷ 41? (a) 23 (b) 230 (c) 2300
  16. 16.Best estimate of 561 ÷ 41? (a) 1400 (b) 140 (c) 14
  17. 17.Best estimate of 2937 ÷ 77? (a) 370 (b) 37 (c) 3700
  18. 18.√94 to 1 decimal place? (a) 9.7 (b) 10.0 (c) 9.8 (d) 9.9
  19. 19.Best estimate of 1114 ÷ 31? (a) 37 (b) 3700 (c) 370
  20. 20.√84 to 1 decimal place? (a) 9.4 (b) 9.3 (c) 9.5 (d) 9.2
  21. 21.√75 to 1 decimal place? (a) 8.9 (b) 8.6 (c) 8.8 (d) 8.7
  22. 22.√65 to 1 decimal place? (a) 8.4 (b) 8.2 (c) 8.3 (d) 8.1
  23. 23.√31 to 1 decimal place? (a) 5.6 (b) 5.3 (c) 5.5 (d) 5.4
  24. 24.√28 to 1 decimal place? (a) 5.4 (b) 5.5 (c) 5.3 (d) 5.2
  25. 25.Best estimate of 6049 ÷ 76? (a) 76 (b) 760 (c) 7600
  26. 26.Best estimate of 1562 ÷ 29? (a) 5200 (b) 520 (c) 52
  27. 27.Best estimate of 1255 ÷ 29? (a) 420 (b) 4200 (c) 42
  28. 28.Best estimate of 3318 ÷ 82? (a) 410 (b) 4100 (c) 41
  29. 29.Best estimate of 3447 ÷ 38? (a) 8600 (b) 860 (c) 86
  30. 30.√67 to 1 decimal place? (a) 8.0 (b) 8.1 (c) 8.2 (d) 7.9
  31. 31.√48 to 1 decimal place? (a) 6.8 (b) 6.9 (c) 7.0 (d) 7.1
  32. 32.√46 to 1 decimal place? (a) 7.0 (b) 6.7 (c) 6.8 (d) 6.9
  33. 33.Best estimate of 684 ÷ 38? (a) 170 (b) 1700 (c) 17
  34. 34.Best estimate of 963 ÷ 38? (a) 2400 (b) 24 (c) 240
  35. 35.Best estimate of 1934 ÷ 31? (a) 6400 (b) 64 (c) 640
  36. 36.Best estimate of 5341 ÷ 61? (a) 890 (b) 89 (c) 8900
  37. 37.Best estimate of 466 ÷ 31? (a) 16 (b) 160 (c) 1600
  38. 38.√34 to 1 decimal place? (a) 6.0 (b) 5.9 (c) 6.1 (d) 5.8
  39. 39.Best estimate of 4217 ÷ 74? (a) 6000 (b) 60 (c) 600
  40. 40.Best estimate of 5463 ÷ 83? (a) 680 (b) 68 (c) 6800

Answer key

  1. 4.5
  2. 74
  3. 21
  4. 9.1
  5. 5.1
  6. 8.8
  7. 30
  8. 68
  9. 54
  10. 54
  11. 19
  12. 8.3
  13. 83
  14. 8.6
  15. 23
  16. 14
  17. 37
  18. 9.7
  19. 37
  20. 9.2
  21. 8.7
  22. 8.1
  23. 5.6
  24. 5.3
  25. 76
  26. 52
  27. 42
  28. 41
  29. 86
  30. 8.2
  31. 6.9
  32. 6.8
  33. 17
  34. 24
  35. 64
  36. 89
  37. 16
  38. 5.8
  39. 60
  40. 68

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