← Rounding off and best estimate lesson New set →

Rounding Off and Estimation Worksheet

Mental maths lesson 15: Rounding off and best estimate · Set 754 · 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 440 + 133? (a) 300 (b) 700 (c) 500
  2. 2.Best estimate of 54 × 18? (a) 100 (b) 10000 (c) 1000
  3. 3.Best estimate of 91 × 87? (a) 8100 (b) 81000 (c) 810
  4. 4.Best estimate of 742 + 700? (a) 1600 (b) 1200 (c) 1400
  5. 5.Best estimate of 384 + 464? (a) 700 (b) 900 (c) 1100
  6. 6.Best estimate of 48 × 13? (a) 50 (b) 500 (c) 5000
  7. 7.Best estimate of 63 × 46? (a) 30000 (b) 300 (c) 3000
  8. 8.Best estimate of 156 + 605? (a) 600 (b) 800 (c) 1000
  9. 9.Best estimate of 67 × 26? (a) 210 (b) 21000 (c) 2100
  10. 10.Best estimate of 90 × 68? (a) 63000 (b) 630 (c) 6300
  11. 11.Best estimate of 73 × 46? (a) 3500 (b) 350 (c) 35000
  12. 12.Best estimate of 468 + 264? (a) 600 (b) 1000 (c) 800
  13. 13.Best estimate of 228 + 200? (a) 600 (b) 400 (c) 200
  14. 14.Best estimate of 40 × 34? (a) 120 (b) 12000 (c) 1200
  15. 15.Best estimate of 96 × 17? (a) 2000 (b) 20000 (c) 200
  16. 16.Best estimate of 47 × 58? (a) 30000 (b) 300 (c) 3000
  17. 17.Best estimate of 77 × 18? (a) 1600 (b) 16000 (c) 160
  18. 18.Best estimate of 98 × 21? (a) 20000 (b) 2000 (c) 200
  19. 19.Best estimate of 83 × 17? (a) 1600 (b) 16000 (c) 160
  20. 20.Best estimate of 51 × 63? (a) 3000 (b) 30000 (c) 300
  21. 21.Best estimate of 44 × 22? (a) 80 (b) 800 (c) 8000
  22. 22.Best estimate of 551 + 207? (a) 1000 (b) 600 (c) 800
  23. 23.Best estimate of 524 + 407? (a) 900 (b) 1100 (c) 700
  24. 24.Best estimate of 58 × 56? (a) 36000 (b) 360 (c) 3600
  25. 25.Best estimate of 16 × 14? (a) 200 (b) 2000 (c) 20
  26. 26.Best estimate of 32 × 16? (a) 6000 (b) 600 (c) 60
  27. 27.Best estimate of 772 + 769? (a) 1800 (b) 1400 (c) 1600
  28. 28.Best estimate of 267 + 513? (a) 1000 (b) 600 (c) 800
  29. 29.Best estimate of 551 + 526? (a) 1100 (b) 1300 (c) 900
  30. 30.Best estimate of 766 + 761? (a) 1600 (b) 1800 (c) 1400
  31. 31.Best estimate of 30 × 34? (a) 9000 (b) 900 (c) 90
  32. 32.Best estimate of 291 + 482? (a) 800 (b) 600 (c) 1000
  33. 33.Best estimate of 63 × 64? (a) 360 (b) 36000 (c) 3600
  34. 34.Best estimate of 710 + 204? (a) 1100 (b) 700 (c) 900
  35. 35.Best estimate of 680 + 223? (a) 900 (b) 700 (c) 1100
  36. 36.Best estimate of 622 + 780? (a) 1200 (b) 1400 (c) 1600
  37. 37.Best estimate of 677 + 209? (a) 900 (b) 1100 (c) 700
  38. 38.Best estimate of 721 + 557? (a) 1500 (b) 1100 (c) 1300
  39. 39.Best estimate of 829 + 797? (a) 1600 (b) 1800 (c) 1400
  40. 40.Best estimate of 46 × 63? (a) 30000 (b) 3000 (c) 300

Answer key

  1. 500
  2. 1000
  3. 8100
  4. 1400
  5. 900
  6. 500
  7. 3000
  8. 800
  9. 2100
  10. 6300
  11. 3500
  12. 800
  13. 400
  14. 1200
  15. 2000
  16. 3000
  17. 1600
  18. 2000
  19. 1600
  20. 3000
  21. 800
  22. 800
  23. 900
  24. 3600
  25. 200
  26. 600
  27. 1600
  28. 800
  29. 1100
  30. 1600
  31. 900
  32. 800
  33. 3600
  34. 900
  35. 900
  36. 1400
  37. 900
  38. 1300
  39. 1600
  40. 3000

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