← Estimate divisions and square roots lesson New set →

Estimating Square Roots and Division Worksheet

Mental maths lesson 27: Estimate divisions and square roots · Set 341 · 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.√77 to 1 decimal place? (a) 8.9 (b) 8.8 (c) 8.7 (d) 8.6
  2. 2.Best estimate of 3037 ÷ 78? (a) 3800 (b) 38 (c) 380
  3. 3.√42 to 1 decimal place? (a) 6.6 (b) 6.8 (c) 6.5 (d) 6.7
  4. 4.Best estimate of 5247 ÷ 77? (a) 660 (b) 6600 (c) 66
  5. 5.Best estimate of 1766 ÷ 76? (a) 220 (b) 2200 (c) 22
  6. 6.Best estimate of 1634 ÷ 28? (a) 54 (b) 540 (c) 5400
  7. 7.√65 to 1 decimal place? (a) 8.2 (b) 8.1 (c) 8.0 (d) 7.9
  8. 8.Best estimate of 1602 ÷ 29? (a) 530 (b) 53 (c) 5300
  9. 9.Best estimate of 1358 ÷ 41? (a) 340 (b) 3400 (c) 34
  10. 10.Best estimate of 4211 ÷ 44? (a) 105 (b) 1050 (c) 10500
  11. 11.√98 to 1 decimal place? (a) 9.6 (b) 9.9 (c) 9.7 (d) 9.8
  12. 12.Best estimate of 4605 ÷ 56? (a) 7700 (b) 770 (c) 77
  13. 13.Best estimate of 2322 ÷ 52? (a) 4600 (b) 460 (c) 46
  14. 14.Best estimate of 2846 ÷ 56? (a) 4700 (b) 470 (c) 47
  15. 15.√90 to 1 decimal place? (a) 9.6 (b) 9.7 (c) 9.5 (d) 9.4
  16. 16.Best estimate of 3315 ÷ 61? (a) 5500 (b) 55 (c) 550
  17. 17.Best estimate of 1244 ÷ 26? (a) 4100 (b) 41 (c) 410
  18. 18.Best estimate of 1668 ÷ 77? (a) 21 (b) 210 (c) 2100
  19. 19.Best estimate of 6546 ÷ 79? (a) 820 (b) 8200 (c) 82
  20. 20.√72 to 1 decimal place? (a) 8.6 (b) 8.5 (c) 8.7 (d) 8.8
  21. 21.Best estimate of 1214 ÷ 23? (a) 610 (b) 6100 (c) 61
  22. 22.Best estimate of 3851 ÷ 46? (a) 770 (b) 77 (c) 7700
  23. 23.√38 to 1 decimal place? (a) 6.0 (b) 6.1 (c) 6.2 (d) 5.9
  24. 24.Best estimate of 1939 ÷ 54? (a) 3900 (b) 390 (c) 39
  25. 25.Best estimate of 1717 ÷ 52? (a) 34 (b) 340 (c) 3400
  26. 26.Best estimate of 680 ÷ 26? (a) 2300 (b) 230 (c) 23
  27. 27.√48 to 1 decimal place? (a) 6.9 (b) 7.0 (c) 6.8 (d) 6.7
  28. 28.√80 to 1 decimal place? (a) 8.8 (b) 8.6 (c) 8.7 (d) 8.9
  29. 29.Best estimate of 1362 ÷ 29? (a) 450 (b) 45 (c) 4500
  30. 30.Best estimate of 2136 ÷ 66? (a) 310 (b) 31 (c) 3100
  31. 31.Best estimate of 1247 ÷ 66? (a) 18 (b) 180 (c) 1800
  32. 32.√59 to 1 decimal place? (a) 7.6 (b) 7.5 (c) 7.4 (d) 7.7
  33. 33.√94 to 1 decimal place? (a) 9.4 (b) 9.5 (c) 9.7 (d) 9.6
  34. 34.Best estimate of 5202 ÷ 81? (a) 650 (b) 6500 (c) 65
  35. 35.Best estimate of 5340 ÷ 62? (a) 89 (b) 8900 (c) 890
  36. 36.Best estimate of 624 ÷ 34? (a) 210 (b) 2100 (c) 21
  37. 37.Best estimate of 1415 ÷ 29? (a) 470 (b) 4700 (c) 47
  38. 38.√86 to 1 decimal place? (a) 9.5 (b) 9.2 (c) 9.3 (d) 9.4
  39. 39.√88 to 1 decimal place? (a) 9.2 (b) 9.4 (c) 9.3 (d) 9.5
  40. 40.Best estimate of 2307 ÷ 54? (a) 4600 (b) 46 (c) 460

Answer key

  1. 8.8
  2. 38
  3. 6.5
  4. 66
  5. 22
  6. 54
  7. 8.1
  8. 53
  9. 34
  10. 105
  11. 9.9
  12. 77
  13. 46
  14. 47
  15. 9.5
  16. 55
  17. 41
  18. 21
  19. 82
  20. 8.5
  21. 61
  22. 77
  23. 6.2
  24. 39
  25. 34
  26. 23
  27. 6.9
  28. 8.9
  29. 45
  30. 31
  31. 18
  32. 7.7
  33. 9.7
  34. 65
  35. 89
  36. 21
  37. 47
  38. 9.3
  39. 9.4
  40. 46

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