← Estimate divisions and square roots lesson New set →

Estimating Square Roots and Division Worksheet

Mental maths lesson 27: Estimate divisions and square roots · Set 295 · 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.√82 to 1 decimal place? (a) 9.4 (b) 9.2 (c) 9.3 (d) 9.1
  2. 2.Best estimate of 1525 ÷ 61? (a) 250 (b) 2500 (c) 25
  3. 3.√27 to 1 decimal place? (a) 5.2 (b) 5.3 (c) 5.4 (d) 5.1
  4. 4.Best estimate of 3930 ÷ 44? (a) 9800 (b) 98 (c) 980
  5. 5.√76 to 1 decimal place? (a) 8.7 (b) 8.5 (c) 8.6 (d) 8.4
  6. 6.Best estimate of 3955 ÷ 42? (a) 99 (b) 9900 (c) 990
  7. 7.Best estimate of 939 ÷ 77? (a) 12 (b) 1200 (c) 120
  8. 8.√45 to 1 decimal place? (a) 6.7 (b) 6.6 (c) 6.8 (d) 6.5
  9. 9.√42 to 1 decimal place? (a) 6.7 (b) 6.6 (c) 6.4 (d) 6.5
  10. 10.√61 to 1 decimal place? (a) 7.9 (b) 8.1 (c) 8.0 (d) 7.8
  11. 11.√40 to 1 decimal place? (a) 6.2 (b) 6.3 (c) 6.1 (d) 6.4
  12. 12.Best estimate of 2625 ÷ 83? (a) 33 (b) 3300 (c) 330
  13. 13.√85 to 1 decimal place? (a) 9.2 (b) 9.4 (c) 9.1 (d) 9.3
  14. 14.√96 to 1 decimal place? (a) 9.9 (b) 9.7 (c) 9.8 (d) 10.0
  15. 15.Best estimate of 5251 ÷ 68? (a) 75 (b) 750 (c) 7500
  16. 16.Best estimate of 1317 ÷ 23? (a) 6600 (b) 66 (c) 660
  17. 17.√24 to 1 decimal place? (a) 5.1 (b) 4.9 (c) 4.8 (d) 5.0
  18. 18.Best estimate of 2516 ÷ 52? (a) 500 (b) 5000 (c) 50
  19. 19.Best estimate of 1998 ÷ 56? (a) 330 (b) 33 (c) 3300
  20. 20.Best estimate of 5952 ÷ 71? (a) 85 (b) 8500 (c) 850
  21. 21.Best estimate of 467 ÷ 21? (a) 230 (b) 2300 (c) 23
  22. 22.√34 to 1 decimal place? (a) 5.9 (b) 5.8 (c) 6.0 (d) 5.7
  23. 23.√29 to 1 decimal place? (a) 5.7 (b) 5.6 (c) 5.5 (d) 5.4
  24. 24.Best estimate of 1536 ÷ 56? (a) 260 (b) 26 (c) 2600
  25. 25.Best estimate of 659 ÷ 26? (a) 22 (b) 2200 (c) 220
  26. 26.Best estimate of 713 ÷ 38? (a) 18 (b) 1800 (c) 180
  27. 27.Best estimate of 2936 ÷ 51? (a) 590 (b) 5900 (c) 59
  28. 28.Best estimate of 1283 ÷ 32? (a) 4300 (b) 430 (c) 43
  29. 29.Best estimate of 1872 ÷ 34? (a) 620 (b) 62 (c) 6200
  30. 30.Best estimate of 3737 ÷ 64? (a) 6200 (b) 62 (c) 620
  31. 31.Best estimate of 2435 ÷ 89? (a) 270 (b) 2700 (c) 27
  32. 32.Best estimate of 1496 ÷ 32? (a) 500 (b) 5000 (c) 50
  33. 33.√59 to 1 decimal place? (a) 7.9 (b) 8.0 (c) 7.8 (d) 7.7
  34. 34.Best estimate of 1335 ÷ 56? (a) 22 (b) 2200 (c) 220
  35. 35.Best estimate of 2854 ÷ 66? (a) 410 (b) 4100 (c) 41
  36. 36.√32 to 1 decimal place? (a) 6.0 (b) 5.7 (c) 5.9 (d) 5.8
  37. 37.Best estimate of 1781 ÷ 37? (a) 4500 (b) 450 (c) 45
  38. 38.Best estimate of 1117 ÷ 44? (a) 28 (b) 280 (c) 2800
  39. 39.Best estimate of 4921 ÷ 81? (a) 620 (b) 6200 (c) 62
  40. 40.Best estimate of 2191 ÷ 32? (a) 73 (b) 730 (c) 7300

Answer key

  1. 9.1
  2. 25
  3. 5.2
  4. 98
  5. 8.7
  6. 99
  7. 12
  8. 6.7
  9. 6.5
  10. 7.8
  11. 6.3
  12. 33
  13. 9.2
  14. 9.8
  15. 75
  16. 66
  17. 4.9
  18. 50
  19. 33
  20. 85
  21. 23
  22. 5.8
  23. 5.4
  24. 26
  25. 22
  26. 18
  27. 59
  28. 43
  29. 62
  30. 62
  31. 27
  32. 50
  33. 7.7
  34. 22
  35. 41
  36. 5.7
  37. 45
  38. 28
  39. 62
  40. 73

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