← Estimate divisions and square roots lesson New set →

Estimating Square Roots and Division Worksheet

Mental maths lesson 27: Estimate divisions and square roots · Set 404 · 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.√72 to 1 decimal place? (a) 8.5 (b) 8.7 (c) 8.6 (d) 8.8
  2. 2.Best estimate of 5079 ÷ 71? (a) 73 (b) 730 (c) 7300
  3. 3.Best estimate of 729 ÷ 28? (a) 240 (b) 24 (c) 2400
  4. 4.√92 to 1 decimal place? (a) 9.6 (b) 9.9 (c) 9.8 (d) 9.7
  5. 5.Best estimate of 1044 ÷ 64? (a) 17 (b) 170 (c) 1700
  6. 6.√74 to 1 decimal place? (a) 8.5 (b) 8.6 (c) 8.4 (d) 8.3
  7. 7.Best estimate of 1129 ÷ 33? (a) 3800 (b) 38 (c) 380
  8. 8.√61 to 1 decimal place? (a) 7.7 (b) 7.8 (c) 7.9 (d) 7.6
  9. 9.Best estimate of 1263 ÷ 36? (a) 32 (b) 320 (c) 3200
  10. 10.√66 to 1 decimal place? (a) 8.1 (b) 8.2 (c) 8.4 (d) 8.3
  11. 11.Best estimate of 4958 ÷ 73? (a) 710 (b) 7100 (c) 71
  12. 12.√56 to 1 decimal place? (a) 7.6 (b) 7.8 (c) 7.7 (d) 7.5
  13. 13.√32 to 1 decimal place? (a) 5.8 (b) 6.0 (c) 5.7 (d) 5.9
  14. 14.√48 to 1 decimal place? (a) 7.1 (b) 7.2 (c) 7.0 (d) 6.9
  15. 15.Best estimate of 637 ÷ 36? (a) 160 (b) 16 (c) 1600
  16. 16.Best estimate of 1843 ÷ 57? (a) 31 (b) 3100 (c) 310
  17. 17.√87 to 1 decimal place? (a) 9.4 (b) 9.2 (c) 9.3 (d) 9.1
  18. 18.Best estimate of 5339 ÷ 67? (a) 76 (b) 760 (c) 7600
  19. 19.√94 to 1 decimal place? (a) 9.8 (b) 9.7 (c) 10.0 (d) 9.9
  20. 20.Best estimate of 4164 ÷ 74? (a) 59 (b) 590 (c) 5900
  21. 21.√65 to 1 decimal place? (a) 7.9 (b) 7.8 (c) 8.0 (d) 8.1
  22. 22.Best estimate of 2462 ÷ 39? (a) 6200 (b) 620 (c) 62
  23. 23.Best estimate of 6369 ÷ 78? (a) 8000 (b) 800 (c) 80
  24. 24.Best estimate of 1307 ÷ 34? (a) 4400 (b) 440 (c) 44
  25. 25.√58 to 1 decimal place? (a) 7.6 (b) 7.9 (c) 7.8 (d) 7.7
  26. 26.√67 to 1 decimal place? (a) 8.4 (b) 8.3 (c) 8.1 (d) 8.2
  27. 27.Best estimate of 3273 ÷ 67? (a) 4700 (b) 47 (c) 470
  28. 28.Best estimate of 1841 ÷ 48? (a) 3700 (b) 37 (c) 370
  29. 29.√24 to 1 decimal place? (a) 5.0 (b) 4.9 (c) 5.1 (d) 4.8
  30. 30.Best estimate of 888 ÷ 29? (a) 300 (b) 3000 (c) 30
  31. 31.Best estimate of 1556 ÷ 29? (a) 5200 (b) 520 (c) 52
  32. 32.Best estimate of 352 ÷ 26? (a) 12 (b) 120 (c) 1200
  33. 33.Best estimate of 2341 ÷ 28? (a) 780 (b) 7800 (c) 78
  34. 34.√21 to 1 decimal place? (a) 4.5 (b) 4.4 (c) 4.3 (d) 4.6
  35. 35.√85 to 1 decimal place? (a) 8.9 (b) 9.2 (c) 9.0 (d) 9.1
  36. 36.Best estimate of 2450 ÷ 27? (a) 820 (b) 8200 (c) 82
  37. 37.Best estimate of 4154 ÷ 86? (a) 46 (b) 460 (c) 4600
  38. 38.Best estimate of 1334 ÷ 72? (a) 19 (b) 1900 (c) 190
  39. 39.Best estimate of 1954 ÷ 27? (a) 650 (b) 6500 (c) 65
  40. 40.Best estimate of 2171 ÷ 47? (a) 430 (b) 4300 (c) 43

Answer key

  1. 8.5
  2. 73
  3. 24
  4. 9.6
  5. 17
  6. 8.6
  7. 38
  8. 7.8
  9. 32
  10. 8.1
  11. 71
  12. 7.5
  13. 5.7
  14. 6.9
  15. 16
  16. 31
  17. 9.3
  18. 76
  19. 9.7
  20. 59
  21. 8.1
  22. 62
  23. 80
  24. 44
  25. 7.6
  26. 8.2
  27. 47
  28. 37
  29. 4.9
  30. 30
  31. 52
  32. 12
  33. 78
  34. 4.6
  35. 9.2
  36. 82
  37. 46
  38. 19
  39. 65
  40. 43

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