← Rounding off and best estimate lesson New set →

Rounding Off and Estimation Worksheet

Mental maths lesson 15: Rounding off and best estimate · Set 88 · 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 56 × 12? (a) 600 (b) 60 (c) 6000
  2. 2.Best estimate of 151 + 673? (a) 900 (b) 1100 (c) 700
  3. 3.Best estimate of 46 × 57? (a) 30000 (b) 300 (c) 3000
  4. 4.Best estimate of 568 + 597? (a) 1400 (b) 1200 (c) 1000
  5. 5.Best estimate of 466 + 476? (a) 800 (b) 1000 (c) 1200
  6. 6.Best estimate of 63 × 88? (a) 540 (b) 5400 (c) 54000
  7. 7.Best estimate of 205 + 433? (a) 800 (b) 600 (c) 400
  8. 8.Best estimate of 63 × 46? (a) 300 (b) 3000 (c) 30000
  9. 9.Best estimate of 606 + 369? (a) 1200 (b) 800 (c) 1000
  10. 10.Best estimate of 70 × 74? (a) 490 (b) 4900 (c) 49000
  11. 11.Best estimate of 498 + 214? (a) 700 (b) 900 (c) 500
  12. 12.Best estimate of 18 × 73? (a) 1400 (b) 140 (c) 14000
  13. 13.Best estimate of 84 × 17? (a) 16000 (b) 160 (c) 1600
  14. 14.Best estimate of 254 + 643? (a) 900 (b) 1100 (c) 700
  15. 15.Best estimate of 66 × 81? (a) 5600 (b) 56000 (c) 560
  16. 16.Best estimate of 472 + 153? (a) 700 (b) 900 (c) 500
  17. 17.Best estimate of 198 + 339? (a) 700 (b) 500 (c) 300
  18. 18.Best estimate of 607 + 122? (a) 700 (b) 900 (c) 500
  19. 19.Best estimate of 82 × 90? (a) 720 (b) 72000 (c) 7200
  20. 20.Best estimate of 179 + 307? (a) 300 (b) 700 (c) 500
  21. 21.Best estimate of 33 × 67? (a) 21000 (b) 210 (c) 2100
  22. 22.Best estimate of 585 + 159? (a) 800 (b) 600 (c) 1000
  23. 23.Best estimate of 26 × 24? (a) 600 (b) 60 (c) 6000
  24. 24.Best estimate of 73 × 51? (a) 35000 (b) 350 (c) 3500
  25. 25.Best estimate of 807 + 527? (a) 1500 (b) 1100 (c) 1300
  26. 26.Best estimate of 98 × 64? (a) 600 (b) 6000 (c) 60000
  27. 27.Best estimate of 800 + 248? (a) 800 (b) 1000 (c) 1200
  28. 28.Best estimate of 63 × 72? (a) 4200 (b) 42000 (c) 420
  29. 29.Best estimate of 67 × 72? (a) 490 (b) 49000 (c) 4900
  30. 30.Best estimate of 32 × 47? (a) 1500 (b) 15000 (c) 150
  31. 31.Best estimate of 37 × 36? (a) 1600 (b) 160 (c) 16000
  32. 32.Best estimate of 868 + 865? (a) 1600 (b) 2000 (c) 1800
  33. 33.Best estimate of 786 + 659? (a) 1500 (b) 1700 (c) 1300
  34. 34.Best estimate of 89 × 96? (a) 9000 (b) 900 (c) 90000
  35. 35.Best estimate of 649 + 446? (a) 1200 (b) 800 (c) 1000
  36. 36.Best estimate of 86 × 70? (a) 63000 (b) 630 (c) 6300
  37. 37.Best estimate of 828 + 669? (a) 1700 (b) 1500 (c) 1300
  38. 38.Best estimate of 834 + 691? (a) 1500 (b) 1300 (c) 1700
  39. 39.Best estimate of 197 + 270? (a) 700 (b) 500 (c) 300
  40. 40.Best estimate of 617 + 273? (a) 900 (b) 700 (c) 1100

Answer key

  1. 600
  2. 900
  3. 3000
  4. 1200
  5. 1000
  6. 5400
  7. 600
  8. 3000
  9. 1000
  10. 4900
  11. 700
  12. 1400
  13. 1600
  14. 900
  15. 5600
  16. 700
  17. 500
  18. 700
  19. 7200
  20. 500
  21. 2100
  22. 800
  23. 600
  24. 3500
  25. 1300
  26. 6000
  27. 1000
  28. 4200
  29. 4900
  30. 1500
  31. 1600
  32. 1800
  33. 1500
  34. 9000
  35. 1000
  36. 6300
  37. 1500
  38. 1500
  39. 500
  40. 900

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