← Rounding off and best estimate lesson New set →

Rounding Off and Estimation Worksheet

Mental maths lesson 15: Rounding off and best estimate · Set 848 · 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 142 + 334? (a) 400 (b) 200 (c) 600
  2. 2.Best estimate of 445 + 472? (a) 900 (b) 1100 (c) 700
  3. 3.Best estimate of 857 + 494? (a) 1400 (b) 1600 (c) 1200
  4. 4.Best estimate of 867 + 405? (a) 1300 (b) 1500 (c) 1100
  5. 5.Best estimate of 49 × 16? (a) 1000 (b) 10000 (c) 100
  6. 6.Best estimate of 232 + 142? (a) 100 (b) 300 (c) 500
  7. 7.Best estimate of 36 × 66? (a) 280 (b) 2800 (c) 28000
  8. 8.Best estimate of 799 + 633? (a) 1200 (b) 1400 (c) 1600
  9. 9.Best estimate of 33 × 61? (a) 1800 (b) 18000 (c) 180
  10. 10.Best estimate of 825 + 834? (a) 1600 (b) 1400 (c) 1800
  11. 11.Best estimate of 452 + 575? (a) 1100 (b) 900 (c) 1300
  12. 12.Best estimate of 59 × 41? (a) 24000 (b) 2400 (c) 240
  13. 13.Best estimate of 69 × 86? (a) 63000 (b) 6300 (c) 630
  14. 14.Best estimate of 76 × 47? (a) 4000 (b) 400 (c) 40000
  15. 15.Best estimate of 48 × 70? (a) 35000 (b) 3500 (c) 350
  16. 16.Best estimate of 22 × 91? (a) 18000 (b) 180 (c) 1800
  17. 17.Best estimate of 779 + 284? (a) 1100 (b) 1300 (c) 900
  18. 18.Best estimate of 688 + 757? (a) 1500 (b) 1700 (c) 1300
  19. 19.Best estimate of 769 + 143? (a) 900 (b) 1100 (c) 700
  20. 20.Best estimate of 730 + 866? (a) 1600 (b) 1800 (c) 1400
  21. 21.Best estimate of 14 × 60? (a) 600 (b) 6000 (c) 60
  22. 22.Best estimate of 793 + 577? (a) 1200 (b) 1600 (c) 1400
  23. 23.Best estimate of 538 + 699? (a) 1000 (b) 1200 (c) 1400
  24. 24.Best estimate of 623 + 170? (a) 800 (b) 1000 (c) 600
  25. 25.Best estimate of 32 × 91? (a) 2700 (b) 270 (c) 27000
  26. 26.Best estimate of 21 × 80? (a) 16000 (b) 160 (c) 1600
  27. 27.Best estimate of 694 + 586? (a) 1500 (b) 1100 (c) 1300
  28. 28.Best estimate of 54 × 37? (a) 20000 (b) 200 (c) 2000
  29. 29.Best estimate of 417 + 483? (a) 1100 (b) 900 (c) 700
  30. 30.Best estimate of 92 × 91? (a) 810 (b) 81000 (c) 8100
  31. 31.Best estimate of 264 + 847? (a) 1100 (b) 900 (c) 1300
  32. 32.Best estimate of 33 × 70? (a) 2100 (b) 21000 (c) 210
  33. 33.Best estimate of 18 × 29? (a) 60 (b) 6000 (c) 600
  34. 34.Best estimate of 737 + 287? (a) 1200 (b) 1000 (c) 800
  35. 35.Best estimate of 508 + 342? (a) 1000 (b) 600 (c) 800
  36. 36.Best estimate of 12 × 16? (a) 200 (b) 20 (c) 2000
  37. 37.Best estimate of 97 × 16? (a) 2000 (b) 20000 (c) 200
  38. 38.Best estimate of 14 × 97? (a) 100 (b) 1000 (c) 10000
  39. 39.Best estimate of 66 × 76? (a) 5600 (b) 56000 (c) 560
  40. 40.Best estimate of 76 × 16? (a) 160 (b) 16000 (c) 1600

Answer key

  1. 400
  2. 900
  3. 1400
  4. 1300
  5. 1000
  6. 300
  7. 2800
  8. 1400
  9. 1800
  10. 1600
  11. 1100
  12. 2400
  13. 6300
  14. 4000
  15. 3500
  16. 1800
  17. 1100
  18. 1500
  19. 900
  20. 1600
  21. 600
  22. 1400
  23. 1200
  24. 800
  25. 2700
  26. 1600
  27. 1300
  28. 2000
  29. 900
  30. 8100
  31. 1100
  32. 2100
  33. 600
  34. 1000
  35. 800
  36. 200
  37. 2000
  38. 1000
  39. 5600
  40. 1600

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