← Rounding off and best estimate lesson New set →

Rounding Off and Estimation Worksheet

Mental maths lesson 15: Rounding off and best estimate · Set 446 · 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 849 + 701? (a) 1700 (b) 1500 (c) 1300
  2. 2.Best estimate of 56 × 24? (a) 120 (b) 1200 (c) 12000
  3. 3.Best estimate of 697 + 859? (a) 1800 (b) 1600 (c) 1400
  4. 4.Best estimate of 92 × 96? (a) 90000 (b) 900 (c) 9000
  5. 5.Best estimate of 592 + 277? (a) 900 (b) 700 (c) 1100
  6. 6.Best estimate of 718 + 348? (a) 1000 (b) 800 (c) 1200
  7. 7.Best estimate of 19 × 77? (a) 160 (b) 1600 (c) 16000
  8. 8.Best estimate of 558 + 627? (a) 1400 (b) 1200 (c) 1000
  9. 9.Best estimate of 87 × 81? (a) 7200 (b) 72000 (c) 720
  10. 10.Best estimate of 389 + 539? (a) 900 (b) 1100 (c) 700
  11. 11.Best estimate of 80 × 68? (a) 560 (b) 56000 (c) 5600
  12. 12.Best estimate of 87 × 56? (a) 54000 (b) 5400 (c) 540
  13. 13.Best estimate of 37 × 23? (a) 80 (b) 8000 (c) 800
  14. 14.Best estimate of 191 + 445? (a) 800 (b) 400 (c) 600
  15. 15.Best estimate of 435 + 124? (a) 700 (b) 300 (c) 500
  16. 16.Best estimate of 866 + 821? (a) 1500 (b) 1700 (c) 1900
  17. 17.Best estimate of 772 + 513? (a) 1100 (b) 1500 (c) 1300
  18. 18.Best estimate of 41 × 31? (a) 12000 (b) 1200 (c) 120
  19. 19.Best estimate of 28 × 30? (a) 9000 (b) 90 (c) 900
  20. 20.Best estimate of 826 + 598? (a) 1600 (b) 1400 (c) 1200
  21. 21.Best estimate of 540 + 599? (a) 1100 (b) 1300 (c) 900
  22. 22.Best estimate of 59 × 40? (a) 24000 (b) 2400 (c) 240
  23. 23.Best estimate of 485 + 141? (a) 800 (b) 400 (c) 600
  24. 24.Best estimate of 62 × 90? (a) 540 (b) 5400 (c) 54000
  25. 25.Best estimate of 59 × 18? (a) 12000 (b) 1200 (c) 120
  26. 26.Best estimate of 661 + 731? (a) 1600 (b) 1400 (c) 1200
  27. 27.Best estimate of 573 + 432? (a) 800 (b) 1000 (c) 1200
  28. 28.Best estimate of 78 × 19? (a) 160 (b) 16000 (c) 1600
  29. 29.Best estimate of 207 + 644? (a) 1000 (b) 600 (c) 800
  30. 30.Best estimate of 74 × 56? (a) 4200 (b) 42000 (c) 420
  31. 31.Best estimate of 34 × 22? (a) 6000 (b) 60 (c) 600
  32. 32.Best estimate of 56 × 12? (a) 600 (b) 6000 (c) 60
  33. 33.Best estimate of 12 × 77? (a) 80 (b) 800 (c) 8000
  34. 34.Best estimate of 623 + 194? (a) 800 (b) 1000 (c) 600
  35. 35.Best estimate of 24 × 27? (a) 600 (b) 6000 (c) 60
  36. 36.Best estimate of 43 × 86? (a) 36000 (b) 360 (c) 3600
  37. 37.Best estimate of 132 + 238? (a) 100 (b) 300 (c) 500
  38. 38.Best estimate of 39 × 86? (a) 360 (b) 36000 (c) 3600
  39. 39.Best estimate of 242 + 510? (a) 700 (b) 900 (c) 500
  40. 40.Best estimate of 614 + 259? (a) 1100 (b) 700 (c) 900

Answer key

  1. 1500
  2. 1200
  3. 1600
  4. 9000
  5. 900
  6. 1000
  7. 1600
  8. 1200
  9. 7200
  10. 900
  11. 5600
  12. 5400
  13. 800
  14. 600
  15. 500
  16. 1700
  17. 1300
  18. 1200
  19. 900
  20. 1400
  21. 1100
  22. 2400
  23. 600
  24. 5400
  25. 1200
  26. 1400
  27. 1000
  28. 1600
  29. 800
  30. 4200
  31. 600
  32. 600
  33. 800
  34. 800
  35. 600
  36. 3600
  37. 300
  38. 3600
  39. 700
  40. 900

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