← Rounding off and best estimate lesson New set →

Rounding Off and Estimation Worksheet

Mental maths lesson 15: Rounding off and best estimate · Set 362 · 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 798 + 201? (a) 800 (b) 1000 (c) 1200
  2. 2.Best estimate of 419 + 795? (a) 1400 (b) 1000 (c) 1200
  3. 3.Best estimate of 49 × 66? (a) 350 (b) 35000 (c) 3500
  4. 4.Best estimate of 30 × 43? (a) 120 (b) 1200 (c) 12000
  5. 5.Best estimate of 76 × 20? (a) 1600 (b) 16000 (c) 160
  6. 6.Best estimate of 93 × 94? (a) 810 (b) 8100 (c) 81000
  7. 7.Best estimate of 624 + 438? (a) 1200 (b) 800 (c) 1000
  8. 8.Best estimate of 747 + 408? (a) 900 (b) 1100 (c) 1300
  9. 9.Best estimate of 811 + 483? (a) 1300 (b) 1500 (c) 1100
  10. 10.Best estimate of 489 + 741? (a) 1200 (b) 1400 (c) 1000
  11. 11.Best estimate of 482 + 555? (a) 1100 (b) 1300 (c) 900
  12. 12.Best estimate of 27 × 86? (a) 270 (b) 2700 (c) 27000
  13. 13.Best estimate of 14 × 86? (a) 900 (b) 9000 (c) 90
  14. 14.Best estimate of 453 + 152? (a) 500 (b) 700 (c) 900
  15. 15.Best estimate of 146 + 262? (a) 600 (b) 400 (c) 200
  16. 16.Best estimate of 306 + 163? (a) 500 (b) 300 (c) 700
  17. 17.Best estimate of 96 × 37? (a) 400 (b) 40000 (c) 4000
  18. 18.Best estimate of 94 × 44? (a) 360 (b) 36000 (c) 3600
  19. 19.Best estimate of 48 × 41? (a) 20000 (b) 2000 (c) 200
  20. 20.Best estimate of 23 × 36? (a) 8000 (b) 80 (c) 800
  21. 21.Best estimate of 600 + 832? (a) 1400 (b) 1200 (c) 1600
  22. 22.Best estimate of 139 + 754? (a) 700 (b) 900 (c) 1100
  23. 23.Best estimate of 94 × 47? (a) 4500 (b) 45000 (c) 450
  24. 24.Best estimate of 80 × 22? (a) 16000 (b) 160 (c) 1600
  25. 25.Best estimate of 695 + 448? (a) 1300 (b) 1100 (c) 900
  26. 26.Best estimate of 72 × 34? (a) 21000 (b) 2100 (c) 210
  27. 27.Best estimate of 19 × 39? (a) 8000 (b) 800 (c) 80
  28. 28.Best estimate of 614 + 744? (a) 1300 (b) 1500 (c) 1100
  29. 29.Best estimate of 51 × 88? (a) 45000 (b) 450 (c) 4500
  30. 30.Best estimate of 619 + 819? (a) 1400 (b) 1600 (c) 1200
  31. 31.Best estimate of 31 × 52? (a) 15000 (b) 1500 (c) 150
  32. 32.Best estimate of 855 + 313? (a) 1400 (b) 1000 (c) 1200
  33. 33.Best estimate of 581 + 549? (a) 900 (b) 1100 (c) 1300
  34. 34.Best estimate of 27 × 40? (a) 1200 (b) 12000 (c) 120
  35. 35.Best estimate of 627 + 820? (a) 1400 (b) 1600 (c) 1200
  36. 36.Best estimate of 425 + 272? (a) 700 (b) 500 (c) 900
  37. 37.Best estimate of 669 + 179? (a) 900 (b) 1100 (c) 700
  38. 38.Best estimate of 81 × 26? (a) 240 (b) 24000 (c) 2400
  39. 39.Best estimate of 21 × 57? (a) 1200 (b) 120 (c) 12000
  40. 40.Best estimate of 82 × 13? (a) 8000 (b) 80 (c) 800

Answer key

  1. 1000
  2. 1200
  3. 3500
  4. 1200
  5. 1600
  6. 8100
  7. 1000
  8. 1100
  9. 1300
  10. 1200
  11. 1100
  12. 2700
  13. 900
  14. 700
  15. 400
  16. 500
  17. 4000
  18. 3600
  19. 2000
  20. 800
  21. 1400
  22. 900
  23. 4500
  24. 1600
  25. 1100
  26. 2100
  27. 800
  28. 1300
  29. 4500
  30. 1400
  31. 1500
  32. 1200
  33. 1100
  34. 1200
  35. 1400
  36. 700
  37. 900
  38. 2400
  39. 1200
  40. 800

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