← Estimate divisions and square roots lesson New set →

Estimating Square Roots and Division Worksheet

Mental maths lesson 27: Estimate divisions and square roots · Set 732 · 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) 7.5 (b) 7.7 (c) 7.6 (d) 7.8
  2. 2.√69 to 1 decimal place? (a) 8.2 (b) 8.3 (c) 8.1 (d) 8.0
  3. 3.Best estimate of 3107 ÷ 54? (a) 620 (b) 62 (c) 6200
  4. 4.√65 to 1 decimal place? (a) 8.3 (b) 8.0 (c) 8.2 (d) 8.1
  5. 5.√75 to 1 decimal place? (a) 8.8 (b) 9.0 (c) 8.9 (d) 8.7
  6. 6.Best estimate of 3637 ÷ 42? (a) 910 (b) 9100 (c) 91
  7. 7.√55 to 1 decimal place? (a) 7.4 (b) 7.2 (c) 7.3 (d) 7.1
  8. 8.√37 to 1 decimal place? (a) 6.0 (b) 6.3 (c) 6.1 (d) 6.2
  9. 9.Best estimate of 2275 ÷ 48? (a) 460 (b) 4600 (c) 46
  10. 10.Best estimate of 1382 ÷ 41? (a) 350 (b) 3500 (c) 35
  11. 11.√85 to 1 decimal place? (a) 9.3 (b) 9.4 (c) 9.1 (d) 9.2
  12. 12.√83 to 1 decimal place? (a) 9.2 (b) 9.3 (c) 9.0 (d) 9.1
  13. 13.√32 to 1 decimal place? (a) 5.8 (b) 5.9 (c) 6.0 (d) 5.7
  14. 14.√87 to 1 decimal place? (a) 9.1 (b) 9.2 (c) 9.3 (d) 9.4
  15. 15.Best estimate of 1654 ÷ 24? (a) 830 (b) 8300 (c) 83
  16. 16.Best estimate of 3561 ÷ 49? (a) 71 (b) 7100 (c) 710
  17. 17.Best estimate of 5538 ÷ 72? (a) 7900 (b) 79 (c) 790
  18. 18.√96 to 1 decimal place? (a) 10.1 (b) 10.0 (c) 9.9 (d) 9.8
  19. 19.Best estimate of 1448 ÷ 52? (a) 2900 (b) 29 (c) 290
  20. 20.√74 to 1 decimal place? (a) 8.5 (b) 8.4 (c) 8.6 (d) 8.7
  21. 21.Best estimate of 925 ÷ 66? (a) 13 (b) 1300 (c) 130
  22. 22.Best estimate of 2488 ÷ 26? (a) 83 (b) 830 (c) 8300
  23. 23.Best estimate of 1568 ÷ 57? (a) 260 (b) 26 (c) 2600
  24. 24.√77 to 1 decimal place? (a) 8.9 (b) 8.7 (c) 9.0 (d) 8.8
  25. 25.√26 to 1 decimal place? (a) 5.4 (b) 5.1 (c) 5.2 (d) 5.3
  26. 26.Best estimate of 692 ÷ 31? (a) 23 (b) 2300 (c) 230
  27. 27.Best estimate of 813 ÷ 42? (a) 20 (b) 2000 (c) 200
  28. 28.Best estimate of 1720 ÷ 48? (a) 340 (b) 3400 (c) 34
  29. 29.Best estimate of 2132 ÷ 27? (a) 71 (b) 710 (c) 7100
  30. 30.Best estimate of 332 ÷ 26? (a) 11 (b) 1100 (c) 110
  31. 31.Best estimate of 530 ÷ 34? (a) 180 (b) 18 (c) 1800
  32. 32.Best estimate of 4167 ÷ 57? (a) 6900 (b) 69 (c) 690
  33. 33.Best estimate of 3785 ÷ 89? (a) 42 (b) 4200 (c) 420
  34. 34.Best estimate of 5453 ÷ 86? (a) 610 (b) 6100 (c) 61
  35. 35.Best estimate of 1215 ÷ 24? (a) 6100 (b) 61 (c) 610
  36. 36.√31 to 1 decimal place? (a) 5.4 (b) 5.5 (c) 5.7 (d) 5.6
  37. 37.√86 to 1 decimal place? (a) 9.3 (b) 9.4 (c) 9.1 (d) 9.2
  38. 38.√88 to 1 decimal place? (a) 9.5 (b) 9.7 (c) 9.4 (d) 9.6
  39. 39.√84 to 1 decimal place? (a) 9.4 (b) 9.2 (c) 9.3 (d) 9.5
  40. 40.Best estimate of 1635 ÷ 29? (a) 55 (b) 5500 (c) 550

Answer key

  1. 7.8
  2. 8.3
  3. 62
  4. 8.1
  5. 8.7
  6. 91
  7. 7.4
  8. 6.1
  9. 46
  10. 35
  11. 9.2
  12. 9.1
  13. 5.7
  14. 9.3
  15. 83
  16. 71
  17. 79
  18. 9.8
  19. 29
  20. 8.6
  21. 13
  22. 83
  23. 26
  24. 8.8
  25. 5.1
  26. 23
  27. 20
  28. 34
  29. 71
  30. 11
  31. 18
  32. 69
  33. 42
  34. 61
  35. 61
  36. 5.6
  37. 9.3
  38. 9.4
  39. 9.2
  40. 55

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