← Rounding off and best estimate lesson New set →

Rounding Off and Estimation Worksheet

Mental maths lesson 15: Rounding off and best estimate · Set 915 · 40 questions
TalentJR

How to do it in your head (Round, then work): Round each number: 2-digit numbers to the nearest ten, 3-digit numbers to the nearest hundred. Do the easy sum with the round numbers. Choose the option closest to your estimate.

NameDateTime takenScore ___ / 40
  1. 1.Best estimate of 84 × 66? (a) 56000 (b) 560 (c) 5600
  2. 2.Best estimate of 813 + 433? (a) 1400 (b) 1200 (c) 1000
  3. 3.Best estimate of 79 × 84? (a) 6400 (b) 64000 (c) 640
  4. 4.Best estimate of 457 + 378? (a) 900 (b) 1100 (c) 700
  5. 5.Best estimate of 56 × 46? (a) 3000 (b) 30000 (c) 300
  6. 6.Best estimate of 56 × 31? (a) 18000 (b) 180 (c) 1800
  7. 7.Best estimate of 28 × 92? (a) 27000 (b) 2700 (c) 270
  8. 8.Best estimate of 33 × 14? (a) 300 (b) 30 (c) 3000
  9. 9.Best estimate of 56 × 68? (a) 42000 (b) 4200 (c) 420
  10. 10.Best estimate of 536 + 612? (a) 1100 (b) 900 (c) 1300
  11. 11.Best estimate of 158 + 487? (a) 900 (b) 500 (c) 700
  12. 12.Best estimate of 653 + 853? (a) 1400 (b) 1600 (c) 1800
  13. 13.Best estimate of 721 + 246? (a) 900 (b) 700 (c) 1100
  14. 14.Best estimate of 467 + 204? (a) 900 (b) 700 (c) 500
  15. 15.Best estimate of 61 × 57? (a) 3600 (b) 360 (c) 36000
  16. 16.Best estimate of 249 + 808? (a) 800 (b) 1200 (c) 1000
  17. 17.Best estimate of 530 + 412? (a) 900 (b) 1100 (c) 700
  18. 18.Best estimate of 568 + 720? (a) 1300 (b) 1500 (c) 1100
  19. 19.Best estimate of 39 × 58? (a) 240 (b) 24000 (c) 2400
  20. 20.Best estimate of 53 × 42? (a) 20000 (b) 2000 (c) 200
  21. 21.Best estimate of 24 × 16? (a) 4000 (b) 40 (c) 400
  22. 22.Best estimate of 464 + 169? (a) 700 (b) 900 (c) 500
  23. 23.Best estimate of 225 + 420? (a) 600 (b) 400 (c) 800
  24. 24.Best estimate of 680 + 165? (a) 700 (b) 900 (c) 1100
  25. 25.Best estimate of 796 + 325? (a) 1100 (b) 1300 (c) 900
  26. 26.Best estimate of 282 + 139? (a) 400 (b) 600 (c) 200
  27. 27.Best estimate of 181 + 606? (a) 1000 (b) 800 (c) 600
  28. 28.Best estimate of 28 × 37? (a) 1200 (b) 120 (c) 12000
  29. 29.Best estimate of 22 × 93? (a) 1800 (b) 18000 (c) 180
  30. 30.Best estimate of 12 × 29? (a) 30 (b) 300 (c) 3000
  31. 31.Best estimate of 76 × 18? (a) 160 (b) 16000 (c) 1600
  32. 32.Best estimate of 32 × 76? (a) 240 (b) 24000 (c) 2400
  33. 33.Best estimate of 816 + 730? (a) 1300 (b) 1700 (c) 1500
  34. 34.Best estimate of 574 + 602? (a) 1200 (b) 1400 (c) 1000
  35. 35.Best estimate of 82 × 54? (a) 40000 (b) 400 (c) 4000
  36. 36.Best estimate of 41 × 26? (a) 1200 (b) 120 (c) 12000
  37. 37.Best estimate of 23 × 84? (a) 1600 (b) 16000 (c) 160
  38. 38.Best estimate of 83 × 94? (a) 7200 (b) 72000 (c) 720
  39. 39.Best estimate of 468 + 694? (a) 1200 (b) 1000 (c) 1400
  40. 40.Best estimate of 14 × 13? (a) 100 (b) 1000 (c) 10

Answer key

  1. 5600
  2. 1200
  3. 6400
  4. 900
  5. 3000
  6. 1800
  7. 2700
  8. 300
  9. 4200
  10. 1100
  11. 700
  12. 1600
  13. 900
  14. 700
  15. 3600
  16. 1000
  17. 900
  18. 1300
  19. 2400
  20. 2000
  21. 400
  22. 700
  23. 600
  24. 900
  25. 1100
  26. 400
  27. 800
  28. 1200
  29. 1800
  30. 300
  31. 1600
  32. 2400
  33. 1500
  34. 1200
  35. 4000
  36. 1200
  37. 1600
  38. 7200
  39. 1200
  40. 100

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