← Rounding off and best estimate lesson New set →

Rounding Off and Estimation Worksheet

Mental maths lesson 15: Rounding off and best estimate · Set 267 · 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 871 + 465? (a) 1400 (b) 1600 (c) 1200
  2. 2.Best estimate of 28 × 64? (a) 1800 (b) 18000 (c) 180
  3. 3.Best estimate of 164 + 193? (a) 600 (b) 200 (c) 400
  4. 4.Best estimate of 728 + 342? (a) 800 (b) 1000 (c) 1200
  5. 5.Best estimate of 559 + 487? (a) 1300 (b) 900 (c) 1100
  6. 6.Best estimate of 96 × 72? (a) 7000 (b) 70000 (c) 700
  7. 7.Best estimate of 91 × 42? (a) 3600 (b) 360 (c) 36000
  8. 8.Best estimate of 73 × 66? (a) 490 (b) 49000 (c) 4900
  9. 9.Best estimate of 512 + 496? (a) 800 (b) 1200 (c) 1000
  10. 10.Best estimate of 555 + 806? (a) 1400 (b) 1200 (c) 1600
  11. 11.Best estimate of 88 × 31? (a) 2700 (b) 27000 (c) 270
  12. 12.Best estimate of 47 × 59? (a) 30000 (b) 3000 (c) 300
  13. 13.Best estimate of 73 × 51? (a) 350 (b) 35000 (c) 3500
  14. 14.Best estimate of 704 + 742? (a) 1600 (b) 1200 (c) 1400
  15. 15.Best estimate of 68 × 52? (a) 35000 (b) 3500 (c) 350
  16. 16.Best estimate of 92 × 34? (a) 2700 (b) 27000 (c) 270
  17. 17.Best estimate of 676 + 495? (a) 1200 (b) 1000 (c) 1400
  18. 18.Best estimate of 20 × 16? (a) 400 (b) 40 (c) 4000
  19. 19.Best estimate of 231 + 387? (a) 400 (b) 800 (c) 600
  20. 20.Best estimate of 71 × 47? (a) 3500 (b) 350 (c) 35000
  21. 21.Best estimate of 144 + 167? (a) 100 (b) 300 (c) 500
  22. 22.Best estimate of 67 × 70? (a) 490 (b) 49000 (c) 4900
  23. 23.Best estimate of 34 × 22? (a) 600 (b) 60 (c) 6000
  24. 24.Best estimate of 73 × 42? (a) 2800 (b) 280 (c) 28000
  25. 25.Best estimate of 31 × 26? (a) 9000 (b) 90 (c) 900
  26. 26.Best estimate of 78 × 64? (a) 48000 (b) 4800 (c) 480
  27. 27.Best estimate of 53 × 20? (a) 100 (b) 1000 (c) 10000
  28. 28.Best estimate of 827 + 291? (a) 1300 (b) 1100 (c) 900
  29. 29.Best estimate of 298 + 195? (a) 700 (b) 300 (c) 500
  30. 30.Best estimate of 28 × 37? (a) 120 (b) 1200 (c) 12000
  31. 31.Best estimate of 37 × 67? (a) 280 (b) 2800 (c) 28000
  32. 32.Best estimate of 48 × 66? (a) 350 (b) 3500 (c) 35000
  33. 33.Best estimate of 17 × 61? (a) 120 (b) 1200 (c) 12000
  34. 34.Best estimate of 16 × 41? (a) 800 (b) 8000 (c) 80
  35. 35.Best estimate of 578 + 814? (a) 1600 (b) 1400 (c) 1200
  36. 36.Best estimate of 86 × 18? (a) 18000 (b) 1800 (c) 180
  37. 37.Best estimate of 66 × 57? (a) 42000 (b) 4200 (c) 420
  38. 38.Best estimate of 80 × 48? (a) 400 (b) 4000 (c) 40000
  39. 39.Best estimate of 47 × 89? (a) 4500 (b) 450 (c) 45000
  40. 40.Best estimate of 247 + 182? (a) 400 (b) 200 (c) 600

Answer key

  1. 1400
  2. 1800
  3. 400
  4. 1000
  5. 1100
  6. 7000
  7. 3600
  8. 4900
  9. 1000
  10. 1400
  11. 2700
  12. 3000
  13. 3500
  14. 1400
  15. 3500
  16. 2700
  17. 1200
  18. 400
  19. 600
  20. 3500
  21. 300
  22. 4900
  23. 600
  24. 2800
  25. 900
  26. 4800
  27. 1000
  28. 1100
  29. 500
  30. 1200
  31. 2800
  32. 3500
  33. 1200
  34. 800
  35. 1400
  36. 1800
  37. 4200
  38. 4000
  39. 4500
  40. 400

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