← Estimate divisions and square roots lesson New set →

Estimating Square Roots and Division Worksheet

Mental maths lesson 27: Estimate divisions and square roots · Set 213 · 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 3321 ÷ 62? (a) 5500 (b) 550 (c) 55
  2. 2.√84 to 1 decimal place? (a) 9.2 (b) 9.4 (c) 9.3 (d) 9.1
  3. 3.√28 to 1 decimal place? (a) 5.6 (b) 5.4 (c) 5.3 (d) 5.5
  4. 4.√83 to 1 decimal place? (a) 9.2 (b) 9.0 (c) 9.3 (d) 9.1
  5. 5.√69 to 1 decimal place? (a) 8.4 (b) 8.2 (c) 8.3 (d) 8.1
  6. 6.√48 to 1 decimal place? (a) 7.1 (b) 7.0 (c) 7.2 (d) 6.9
  7. 7.Best estimate of 3295 ÷ 64? (a) 55 (b) 550 (c) 5500
  8. 8.√35 to 1 decimal place? (a) 5.9 (b) 6.1 (c) 6.0 (d) 5.8
  9. 9.Best estimate of 3782 ÷ 84? (a) 4700 (b) 470 (c) 47
  10. 10.Best estimate of 585 ÷ 26? (a) 20 (b) 200 (c) 2000
  11. 11.Best estimate of 537 ÷ 41? (a) 1300 (b) 130 (c) 13
  12. 12.Best estimate of 877 ÷ 42? (a) 22 (b) 2200 (c) 220
  13. 13.Best estimate of 2855 ÷ 78? (a) 36 (b) 360 (c) 3600
  14. 14.Best estimate of 6003 ÷ 67? (a) 8600 (b) 86 (c) 860
  15. 15.Best estimate of 2661 ÷ 82? (a) 33 (b) 330 (c) 3300
  16. 16.√32 to 1 decimal place? (a) 5.9 (b) 5.8 (c) 5.6 (d) 5.7
  17. 17.√53 to 1 decimal place? (a) 7.2 (b) 7.3 (c) 7.1 (d) 7.4
  18. 18.Best estimate of 503 ÷ 24? (a) 250 (b) 2500 (c) 25
  19. 19.Best estimate of 860 ÷ 53? (a) 170 (b) 1700 (c) 17
  20. 20.Best estimate of 533 ÷ 36? (a) 130 (b) 13 (c) 1300
  21. 21.Best estimate of 2161 ÷ 36? (a) 54 (b) 5400 (c) 540
  22. 22.√88 to 1 decimal place? (a) 9.4 (b) 9.6 (c) 9.5 (d) 9.3
  23. 23.√71 to 1 decimal place? (a) 8.6 (b) 8.3 (c) 8.4 (d) 8.5
  24. 24.Best estimate of 1172 ÷ 72? (a) 1700 (b) 170 (c) 17
  25. 25.√94 to 1 decimal place? (a) 9.7 (b) 9.8 (c) 9.6 (d) 9.9
  26. 26.Best estimate of 4019 ÷ 66? (a) 57 (b) 570 (c) 5700
  27. 27.√46 to 1 decimal place? (a) 6.9 (b) 7.0 (c) 6.8 (d) 6.7
  28. 28.√26 to 1 decimal place? (a) 5.3 (b) 5.2 (c) 5.4 (d) 5.1
  29. 29.√56 to 1 decimal place? (a) 7.5 (b) 7.4 (c) 7.7 (d) 7.6
  30. 30.√24 to 1 decimal place? (a) 4.9 (b) 5.1 (c) 5.0 (d) 4.8
  31. 31.Best estimate of 1870 ÷ 28? (a) 620 (b) 62 (c) 6200
  32. 32.Best estimate of 2369 ÷ 64? (a) 3900 (b) 390 (c) 39
  33. 33.Best estimate of 1405 ÷ 29? (a) 470 (b) 4700 (c) 47
  34. 34.√65 to 1 decimal place? (a) 7.9 (b) 8.1 (c) 8.0 (d) 8.2
  35. 35.√74 to 1 decimal place? (a) 8.5 (b) 8.3 (c) 8.4 (d) 8.6
  36. 36.Best estimate of 2161 ÷ 66? (a) 3100 (b) 310 (c) 31
  37. 37.Best estimate of 386 ÷ 26? (a) 130 (b) 13 (c) 1300
  38. 38.Best estimate of 2284 ÷ 41? (a) 570 (b) 5700 (c) 57
  39. 39.Best estimate of 2752 ÷ 32? (a) 9200 (b) 920 (c) 92
  40. 40.Best estimate of 3799 ÷ 54? (a) 760 (b) 76 (c) 7600

Answer key

  1. 55
  2. 9.2
  3. 5.3
  4. 9.1
  5. 8.3
  6. 6.9
  7. 55
  8. 5.9
  9. 47
  10. 20
  11. 13
  12. 22
  13. 36
  14. 86
  15. 33
  16. 5.7
  17. 7.3
  18. 25
  19. 17
  20. 13
  21. 54
  22. 9.4
  23. 8.4
  24. 17
  25. 9.7
  26. 57
  27. 6.8
  28. 5.1
  29. 7.5
  30. 4.9
  31. 62
  32. 39
  33. 47
  34. 8.1
  35. 8.6
  36. 31
  37. 13
  38. 57
  39. 92
  40. 76

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