← Rounding off and best estimate lesson New set →

Rounding Off and Estimation Worksheet

Mental maths lesson 15: Rounding off and best estimate · Set 441 · 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 66 × 14? (a) 70 (b) 7000 (c) 700
  2. 2.Best estimate of 76 × 37? (a) 32000 (b) 320 (c) 3200
  3. 3.Best estimate of 72 × 66? (a) 490 (b) 49000 (c) 4900
  4. 4.Best estimate of 268 + 619? (a) 700 (b) 1100 (c) 900
  5. 5.Best estimate of 359 + 397? (a) 1000 (b) 800 (c) 600
  6. 6.Best estimate of 28 × 24? (a) 6000 (b) 600 (c) 60
  7. 7.Best estimate of 459 + 457? (a) 1200 (b) 800 (c) 1000
  8. 8.Best estimate of 226 + 720? (a) 700 (b) 1100 (c) 900
  9. 9.Best estimate of 84 × 48? (a) 40000 (b) 4000 (c) 400
  10. 10.Best estimate of 154 + 663? (a) 700 (b) 900 (c) 1100
  11. 11.Best estimate of 270 + 728? (a) 800 (b) 1200 (c) 1000
  12. 12.Best estimate of 49 × 46? (a) 25000 (b) 250 (c) 2500
  13. 13.Best estimate of 13 × 57? (a) 6000 (b) 600 (c) 60
  14. 14.Best estimate of 524 + 574? (a) 900 (b) 1300 (c) 1100
  15. 15.Best estimate of 452 + 627? (a) 1300 (b) 900 (c) 1100
  16. 16.Best estimate of 52 × 16? (a) 1000 (b) 10000 (c) 100
  17. 17.Best estimate of 379 + 790? (a) 1200 (b) 1000 (c) 1400
  18. 18.Best estimate of 26 × 60? (a) 1800 (b) 180 (c) 18000
  19. 19.Best estimate of 86 × 46? (a) 4500 (b) 45000 (c) 450
  20. 20.Best estimate of 505 + 259? (a) 1000 (b) 800 (c) 600
  21. 21.Best estimate of 27 × 57? (a) 1800 (b) 18000 (c) 180
  22. 22.Best estimate of 618 + 155? (a) 800 (b) 600 (c) 1000
  23. 23.Best estimate of 785 + 358? (a) 1200 (b) 1000 (c) 1400
  24. 24.Best estimate of 235 + 648? (a) 1000 (b) 600 (c) 800
  25. 25.Best estimate of 41 × 31? (a) 1200 (b) 12000 (c) 120
  26. 26.Best estimate of 509 + 244? (a) 900 (b) 700 (c) 500
  27. 27.Best estimate of 23 × 37? (a) 8000 (b) 80 (c) 800
  28. 28.Best estimate of 61 × 64? (a) 3600 (b) 36000 (c) 360
  29. 29.Best estimate of 266 + 708? (a) 1000 (b) 800 (c) 1200
  30. 30.Best estimate of 63 × 54? (a) 300 (b) 3000 (c) 30000
  31. 31.Best estimate of 301 + 574? (a) 1100 (b) 900 (c) 700
  32. 32.Best estimate of 443 + 834? (a) 1200 (b) 1000 (c) 1400
  33. 33.Best estimate of 185 + 602? (a) 800 (b) 600 (c) 1000
  34. 34.Best estimate of 97 × 82? (a) 80000 (b) 800 (c) 8000
  35. 35.Best estimate of 19 × 19? (a) 400 (b) 40 (c) 4000
  36. 36.Best estimate of 66 × 20? (a) 1400 (b) 14000 (c) 140
  37. 37.Best estimate of 73 × 66? (a) 4900 (b) 49000 (c) 490
  38. 38.Best estimate of 17 × 28? (a) 600 (b) 6000 (c) 60
  39. 39.Best estimate of 73 × 30? (a) 210 (b) 2100 (c) 21000
  40. 40.Best estimate of 303 + 233? (a) 700 (b) 300 (c) 500

Answer key

  1. 700
  2. 3200
  3. 4900
  4. 900
  5. 800
  6. 600
  7. 1000
  8. 900
  9. 4000
  10. 900
  11. 1000
  12. 2500
  13. 600
  14. 1100
  15. 1100
  16. 1000
  17. 1200
  18. 1800
  19. 4500
  20. 800
  21. 1800
  22. 800
  23. 1200
  24. 800
  25. 1200
  26. 700
  27. 800
  28. 3600
  29. 1000
  30. 3000
  31. 900
  32. 1200
  33. 800
  34. 8000
  35. 400
  36. 1400
  37. 4900
  38. 600
  39. 2100
  40. 500

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