← Estimate divisions and square roots lesson New set →

Estimating Square Roots and Division Worksheet

Mental maths lesson 27: Estimate divisions and square roots · Set 313 · 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 1002 ÷ 43? (a) 250 (b) 2500 (c) 25
  2. 2.√69 to 1 decimal place? (a) 8.4 (b) 8.3 (c) 8.2 (d) 8.1
  3. 3.√44 to 1 decimal place? (a) 6.4 (b) 6.6 (c) 6.5 (d) 6.7
  4. 4.√28 to 1 decimal place? (a) 5.2 (b) 5.4 (c) 5.3 (d) 5.5
  5. 5.√83 to 1 decimal place? (a) 9.2 (b) 9.0 (c) 8.9 (d) 9.1
  6. 6.√26 to 1 decimal place? (a) 5.3 (b) 5.1 (c) 5.2 (d) 5.4
  7. 7.Best estimate of 1969 ÷ 57? (a) 330 (b) 3300 (c) 33
  8. 8.Best estimate of 6631 ÷ 78? (a) 8300 (b) 83 (c) 830
  9. 9.Best estimate of 1507 ÷ 89? (a) 170 (b) 1700 (c) 17
  10. 10.Best estimate of 3291 ÷ 52? (a) 6600 (b) 66 (c) 660
  11. 11.Best estimate of 7300 ÷ 78? (a) 91 (b) 910 (c) 9100
  12. 12.Best estimate of 3241 ÷ 74? (a) 46 (b) 460 (c) 4600
  13. 13.Best estimate of 2758 ÷ 36? (a) 69 (b) 690 (c) 6900
  14. 14.√50 to 1 decimal place? (a) 7.0 (b) 7.2 (c) 6.9 (d) 7.1
  15. 15.Best estimate of 3994 ÷ 72? (a) 5700 (b) 570 (c) 57
  16. 16.Best estimate of 3107 ÷ 52? (a) 6200 (b) 620 (c) 62
  17. 17.√32 to 1 decimal place? (a) 5.5 (b) 5.7 (c) 5.6 (d) 5.8
  18. 18.√38 to 1 decimal place? (a) 6.2 (b) 6.3 (c) 6.4 (d) 6.5
  19. 19.Best estimate of 3465 ÷ 39? (a) 87 (b) 8700 (c) 870
  20. 20.Best estimate of 3355 ÷ 68? (a) 480 (b) 4800 (c) 48
  21. 21.√82 to 1 decimal place? (a) 9.0 (b) 9.3 (c) 9.1 (d) 9.2
  22. 22.Best estimate of 4845 ÷ 79? (a) 61 (b) 610 (c) 6100
  23. 23.√88 to 1 decimal place? (a) 9.3 (b) 9.5 (c) 9.4 (d) 9.6
  24. 24.√22 to 1 decimal place? (a) 4.6 (b) 4.5 (c) 4.7 (d) 4.4
  25. 25.√74 to 1 decimal place? (a) 8.9 (b) 8.8 (c) 8.7 (d) 8.6
  26. 26.Best estimate of 1511 ÷ 41? (a) 38 (b) 3800 (c) 380
  27. 27.Best estimate of 1065 ÷ 83? (a) 13 (b) 1300 (c) 130
  28. 28.Best estimate of 947 ÷ 66? (a) 140 (b) 14 (c) 1400
  29. 29.Best estimate of 1687 ÷ 22? (a) 840 (b) 84 (c) 8400
  30. 30.Best estimate of 5018 ÷ 77? (a) 6300 (b) 630 (c) 63
  31. 31.Best estimate of 2606 ÷ 72? (a) 3700 (b) 370 (c) 37
  32. 32.Best estimate of 775 ÷ 22? (a) 3900 (b) 39 (c) 390
  33. 33.Best estimate of 2111 ÷ 82? (a) 2600 (b) 260 (c) 26
  34. 34.Best estimate of 5618 ÷ 82? (a) 700 (b) 7000 (c) 70
  35. 35.Best estimate of 4406 ÷ 53? (a) 8800 (b) 88 (c) 880
  36. 36.Best estimate of 3827 ÷ 51? (a) 77 (b) 770 (c) 7700
  37. 37.Best estimate of 4085 ÷ 43? (a) 1020 (b) 10200 (c) 102
  38. 38.√59 to 1 decimal place? (a) 7.4 (b) 7.7 (c) 7.6 (d) 7.5
  39. 39.Best estimate of 677 ÷ 24? (a) 340 (b) 3400 (c) 34
  40. 40.Best estimate of 5566 ÷ 63? (a) 9300 (b) 930 (c) 93

Answer key

  1. 25
  2. 8.3
  3. 6.6
  4. 5.3
  5. 9.1
  6. 5.1
  7. 33
  8. 83
  9. 17
  10. 66
  11. 91
  12. 46
  13. 69
  14. 7.1
  15. 57
  16. 62
  17. 5.7
  18. 6.2
  19. 87
  20. 48
  21. 9.1
  22. 61
  23. 9.4
  24. 4.7
  25. 8.6
  26. 38
  27. 13
  28. 14
  29. 84
  30. 63
  31. 37
  32. 39
  33. 26
  34. 70
  35. 88
  36. 77
  37. 102
  38. 7.7
  39. 34
  40. 93

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