← Estimate divisions and square roots lesson New set →

Estimating Square Roots and Division Worksheet

Mental maths lesson 27: Estimate divisions and square roots · Set 853 · 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 958 ÷ 63? (a) 16 (b) 160 (c) 1600
  2. 2.√34 to 1 decimal place? (a) 5.9 (b) 5.8 (c) 6.1 (d) 6.0
  3. 3.√35 to 1 decimal place? (a) 5.8 (b) 6.0 (c) 5.9 (d) 5.7
  4. 4.√74 to 1 decimal place? (a) 8.6 (b) 8.4 (c) 8.5 (d) 8.7
  5. 5.Best estimate of 2539 ÷ 36? (a) 63 (b) 6300 (c) 630
  6. 6.√40 to 1 decimal place? (a) 6.3 (b) 6.4 (c) 6.1 (d) 6.2
  7. 7.Best estimate of 2679 ÷ 29? (a) 890 (b) 8900 (c) 89
  8. 8.Best estimate of 1502 ÷ 41? (a) 38 (b) 380 (c) 3800
  9. 9.Best estimate of 5858 ÷ 62? (a) 9800 (b) 98 (c) 980
  10. 10.Best estimate of 2543 ÷ 48? (a) 51 (b) 510 (c) 5100
  11. 11.√47 to 1 decimal place? (a) 6.8 (b) 6.6 (c) 6.9 (d) 6.7
  12. 12.√56 to 1 decimal place? (a) 7.6 (b) 7.4 (c) 7.3 (d) 7.5
  13. 13.Best estimate of 2014 ÷ 83? (a) 250 (b) 2500 (c) 25
  14. 14.Best estimate of 511 ÷ 27? (a) 170 (b) 17 (c) 1700
  15. 15.Best estimate of 724 ÷ 26? (a) 24 (b) 240 (c) 2400
  16. 16.Best estimate of 1384 ÷ 32? (a) 460 (b) 4600 (c) 46
  17. 17.√24 to 1 decimal place? (a) 4.8 (b) 4.9 (c) 4.7 (d) 4.6
  18. 18.√52 to 1 decimal place? (a) 6.9 (b) 7.2 (c) 7.1 (d) 7.0
  19. 19.Best estimate of 3306 ÷ 36? (a) 8300 (b) 830 (c) 83
  20. 20.√72 to 1 decimal place? (a) 8.8 (b) 8.6 (c) 8.5 (d) 8.7
  21. 21.Best estimate of 4923 ÷ 52? (a) 9800 (b) 98 (c) 980
  22. 22.Best estimate of 5926 ÷ 86? (a) 66 (b) 6600 (c) 660
  23. 23.Best estimate of 1918 ÷ 63? (a) 32 (b) 320 (c) 3200
  24. 24.√38 to 1 decimal place? (a) 6.2 (b) 6.1 (c) 6.0 (d) 5.9
  25. 25.√58 to 1 decimal place? (a) 7.6 (b) 7.5 (c) 7.4 (d) 7.7
  26. 26.Best estimate of 899 ÷ 52? (a) 180 (b) 1800 (c) 18
  27. 27.√29 to 1 decimal place? (a) 5.3 (b) 5.4 (c) 5.5 (d) 5.6
  28. 28.Best estimate of 3033 ÷ 54? (a) 6100 (b) 610 (c) 61
  29. 29.Best estimate of 7032 ÷ 89? (a) 7800 (b) 78 (c) 780
  30. 30.Best estimate of 1928 ÷ 42? (a) 4800 (b) 480 (c) 48
  31. 31.√55 to 1 decimal place? (a) 7.3 (b) 7.5 (c) 7.4 (d) 7.2
  32. 32.Best estimate of 1848 ÷ 31? (a) 620 (b) 6200 (c) 62
  33. 33.√69 to 1 decimal place? (a) 8.2 (b) 8.4 (c) 8.1 (d) 8.3
  34. 34.Best estimate of 1742 ÷ 29? (a) 580 (b) 58 (c) 5800
  35. 35.Best estimate of 1485 ÷ 44? (a) 3700 (b) 370 (c) 37
  36. 36.Best estimate of 3651 ÷ 72? (a) 520 (b) 52 (c) 5200
  37. 37.√71 to 1 decimal place? (a) 8.4 (b) 8.1 (c) 8.2 (d) 8.3
  38. 38.Best estimate of 1841 ÷ 36? (a) 46 (b) 4600 (c) 460
  39. 39.√75 to 1 decimal place? (a) 8.6 (b) 8.5 (c) 8.4 (d) 8.7
  40. 40.√77 to 1 decimal place? (a) 8.9 (b) 8.8 (c) 8.7 (d) 9.0

Answer key

  1. 16
  2. 5.8
  3. 5.9
  4. 8.6
  5. 63
  6. 6.3
  7. 89
  8. 38
  9. 98
  10. 51
  11. 6.9
  12. 7.5
  13. 25
  14. 17
  15. 24
  16. 46
  17. 4.9
  18. 7.2
  19. 83
  20. 8.5
  21. 98
  22. 66
  23. 32
  24. 6.2
  25. 7.6
  26. 18
  27. 5.4
  28. 61
  29. 78
  30. 48
  31. 7.4
  32. 62
  33. 8.3
  34. 58
  35. 37
  36. 52
  37. 8.4
  38. 46
  39. 8.7
  40. 8.8

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