← Rounding off and best estimate lesson New set →

Rounding Off and Estimation Worksheet

Mental maths lesson 15: Rounding off and best estimate · Set 576 · 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 52 × 56? (a) 300 (b) 30000 (c) 3000
  2. 2.Best estimate of 601 + 807? (a) 1400 (b) 1600 (c) 1200
  3. 3.Best estimate of 27 × 80? (a) 240 (b) 2400 (c) 24000
  4. 4.Best estimate of 88 × 93? (a) 810 (b) 8100 (c) 81000
  5. 5.Best estimate of 31 × 24? (a) 6000 (b) 60 (c) 600
  6. 6.Best estimate of 432 + 685? (a) 1100 (b) 900 (c) 1300
  7. 7.Best estimate of 66 × 21? (a) 14000 (b) 140 (c) 1400
  8. 8.Best estimate of 206 + 520? (a) 500 (b) 700 (c) 900
  9. 9.Best estimate of 276 + 205? (a) 700 (b) 300 (c) 500
  10. 10.Best estimate of 225 + 635? (a) 1000 (b) 800 (c) 600
  11. 11.Best estimate of 88 × 22? (a) 1800 (b) 180 (c) 18000
  12. 12.Best estimate of 36 × 39? (a) 16000 (b) 160 (c) 1600
  13. 13.Best estimate of 153 + 681? (a) 1100 (b) 900 (c) 700
  14. 14.Best estimate of 167 + 215? (a) 400 (b) 200 (c) 600
  15. 15.Best estimate of 218 + 157? (a) 400 (b) 200 (c) 600
  16. 16.Best estimate of 244 + 190? (a) 200 (b) 600 (c) 400
  17. 17.Best estimate of 710 + 244? (a) 1100 (b) 700 (c) 900
  18. 18.Best estimate of 21 × 26? (a) 60 (b) 600 (c) 6000
  19. 19.Best estimate of 318 + 437? (a) 700 (b) 500 (c) 900
  20. 20.Best estimate of 671 + 135? (a) 1000 (b) 800 (c) 600
  21. 21.Best estimate of 13 × 23? (a) 200 (b) 20 (c) 2000
  22. 22.Best estimate of 384 + 600? (a) 1200 (b) 800 (c) 1000
  23. 23.Best estimate of 263 + 348? (a) 400 (b) 800 (c) 600
  24. 24.Best estimate of 799 + 771? (a) 1800 (b) 1600 (c) 1400
  25. 25.Best estimate of 31 × 12? (a) 3000 (b) 30 (c) 300
  26. 26.Best estimate of 51 × 83? (a) 40000 (b) 4000 (c) 400
  27. 27.Best estimate of 598 + 162? (a) 600 (b) 800 (c) 1000
  28. 28.Best estimate of 56 × 24? (a) 1200 (b) 12000 (c) 120
  29. 29.Best estimate of 87 × 59? (a) 5400 (b) 540 (c) 54000
  30. 30.Best estimate of 81 × 49? (a) 4000 (b) 400 (c) 40000
  31. 31.Best estimate of 57 × 54? (a) 3000 (b) 30000 (c) 300
  32. 32.Best estimate of 47 × 74? (a) 3500 (b) 35000 (c) 350
  33. 33.Best estimate of 228 + 188? (a) 400 (b) 200 (c) 600
  34. 34.Best estimate of 96 × 13? (a) 100 (b) 10000 (c) 1000
  35. 35.Best estimate of 56 × 59? (a) 3600 (b) 360 (c) 36000
  36. 36.Best estimate of 314 + 230? (a) 700 (b) 300 (c) 500
  37. 37.Best estimate of 69 × 89? (a) 6300 (b) 63000 (c) 630
  38. 38.Best estimate of 136 + 144? (a) 200 (b) 400 (c) 0
  39. 39.Best estimate of 67 × 61? (a) 42000 (b) 4200 (c) 420
  40. 40.Best estimate of 211 + 464? (a) 500 (b) 700 (c) 900

Answer key

  1. 3000
  2. 1400
  3. 2400
  4. 8100
  5. 600
  6. 1100
  7. 1400
  8. 700
  9. 500
  10. 800
  11. 1800
  12. 1600
  13. 900
  14. 400
  15. 400
  16. 400
  17. 900
  18. 600
  19. 700
  20. 800
  21. 200
  22. 1000
  23. 600
  24. 1600
  25. 300
  26. 4000
  27. 800
  28. 1200
  29. 5400
  30. 4000
  31. 3000
  32. 3500
  33. 400
  34. 1000
  35. 3600
  36. 500
  37. 6300
  38. 200
  39. 4200
  40. 700

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