← Estimate divisions and square roots lesson New set →

Estimating Square Roots and Division Worksheet

Mental maths lesson 27: Estimate divisions and square roots · Set 961 · 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.√61 to 1 decimal place? (a) 8.0 (b) 7.7 (c) 7.8 (d) 7.9
  2. 2.Best estimate of 5636 ÷ 59? (a) 9400 (b) 94 (c) 940
  3. 3.Best estimate of 2400 ÷ 87? (a) 270 (b) 27 (c) 2700
  4. 4.√29 to 1 decimal place? (a) 5.3 (b) 5.1 (c) 5.2 (d) 5.4
  5. 5.Best estimate of 4867 ÷ 64? (a) 810 (b) 8100 (c) 81
  6. 6.Best estimate of 858 ÷ 56? (a) 14 (b) 1400 (c) 140
  7. 7.Best estimate of 2254 ÷ 79? (a) 280 (b) 28 (c) 2800
  8. 8.Best estimate of 2317 ÷ 43? (a) 580 (b) 58 (c) 5800
  9. 9.√65 to 1 decimal place? (a) 8.1 (b) 8.0 (c) 8.2 (d) 7.9
  10. 10.√26 to 1 decimal place? (a) 5.1 (b) 5.2 (c) 5.0 (d) 4.9
  11. 11.Best estimate of 2146 ÷ 36? (a) 5400 (b) 540 (c) 54
  12. 12.Best estimate of 1912 ÷ 44? (a) 480 (b) 4800 (c) 48
  13. 13.√75 to 1 decimal place? (a) 8.5 (b) 8.4 (c) 8.6 (d) 8.7
  14. 14.√76 to 1 decimal place? (a) 8.5 (b) 8.6 (c) 8.7 (d) 8.4
  15. 15.Best estimate of 1453 ÷ 34? (a) 4800 (b) 48 (c) 480
  16. 16.Best estimate of 1885 ÷ 27? (a) 630 (b) 63 (c) 6300
  17. 17.Best estimate of 1963 ÷ 56? (a) 3300 (b) 33 (c) 330
  18. 18.Best estimate of 682 ÷ 36? (a) 170 (b) 17 (c) 1700
  19. 19.Best estimate of 979 ÷ 27? (a) 330 (b) 3300 (c) 33
  20. 20.√28 to 1 decimal place? (a) 5.1 (b) 5.3 (c) 5.2 (d) 5.0
  21. 21.√55 to 1 decimal place? (a) 7.4 (b) 7.2 (c) 7.3 (d) 7.5
  22. 22.√80 to 1 decimal place? (a) 8.6 (b) 8.9 (c) 8.7 (d) 8.8
  23. 23.√34 to 1 decimal place? (a) 5.9 (b) 5.8 (c) 6.0 (d) 5.7
  24. 24.Best estimate of 5477 ÷ 61? (a) 9100 (b) 91 (c) 910
  25. 25.Best estimate of 2311 ÷ 58? (a) 39 (b) 3900 (c) 390
  26. 26.√74 to 1 decimal place? (a) 8.8 (b) 8.6 (c) 8.7 (d) 8.5
  27. 27.√53 to 1 decimal place? (a) 7.0 (b) 7.3 (c) 7.1 (d) 7.2
  28. 28.Best estimate of 4331 ÷ 61? (a) 720 (b) 7200 (c) 72
  29. 29.√63 to 1 decimal place? (a) 8.1 (b) 8.0 (c) 8.2 (d) 7.9
  30. 30.√71 to 1 decimal place? (a) 8.5 (b) 8.4 (c) 8.3 (d) 8.6
  31. 31.√56 to 1 decimal place? (a) 7.4 (b) 7.5 (c) 7.3 (d) 7.6
  32. 32.Best estimate of 5531 ÷ 61? (a) 92 (b) 920 (c) 9200
  33. 33.Best estimate of 4257 ÷ 88? (a) 470 (b) 47 (c) 4700
  34. 34.√27 to 1 decimal place? (a) 5.4 (b) 5.5 (c) 5.3 (d) 5.2
  35. 35.Best estimate of 3823 ÷ 42? (a) 9600 (b) 960 (c) 96
  36. 36.Best estimate of 1699 ÷ 76? (a) 210 (b) 2100 (c) 21
  37. 37.Best estimate of 1062 ÷ 76? (a) 130 (b) 13 (c) 1300
  38. 38.Best estimate of 674 ÷ 52? (a) 130 (b) 13 (c) 1300
  39. 39.√23 to 1 decimal place? (a) 4.7 (b) 5.0 (c) 4.9 (d) 4.8
  40. 40.Best estimate of 313 ÷ 26? (a) 1000 (b) 10 (c) 100

Answer key

  1. 7.8
  2. 94
  3. 27
  4. 5.4
  5. 81
  6. 14
  7. 28
  8. 58
  9. 8.1
  10. 5.1
  11. 54
  12. 48
  13. 8.7
  14. 8.7
  15. 48
  16. 63
  17. 33
  18. 17
  19. 33
  20. 5.3
  21. 7.4
  22. 8.9
  23. 5.8
  24. 91
  25. 39
  26. 8.6
  27. 7.3
  28. 72
  29. 7.9
  30. 8.4
  31. 7.5
  32. 92
  33. 47
  34. 5.2
  35. 96
  36. 21
  37. 13
  38. 13
  39. 4.8
  40. 10

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