← Rounding off and best estimate lesson New set →

Rounding Off and Estimation Worksheet

Mental maths lesson 15: Rounding off and best estimate · Set 494 · 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 835 + 814? (a) 1600 (b) 1800 (c) 1400
  2. 2.Best estimate of 69 × 86? (a) 6300 (b) 630 (c) 63000
  3. 3.Best estimate of 630 + 464? (a) 1100 (b) 900 (c) 1300
  4. 4.Best estimate of 644 + 169? (a) 800 (b) 600 (c) 1000
  5. 5.Best estimate of 38 × 60? (a) 240 (b) 24000 (c) 2400
  6. 6.Best estimate of 647 + 817? (a) 1200 (b) 1600 (c) 1400
  7. 7.Best estimate of 22 × 86? (a) 18000 (b) 1800 (c) 180
  8. 8.Best estimate of 43 × 19? (a) 8000 (b) 800 (c) 80
  9. 9.Best estimate of 70 × 58? (a) 420 (b) 4200 (c) 42000
  10. 10.Best estimate of 420 + 535? (a) 900 (b) 1100 (c) 700
  11. 11.Best estimate of 628 + 572? (a) 1200 (b) 1000 (c) 1400
  12. 12.Best estimate of 36 × 60? (a) 240 (b) 2400 (c) 24000
  13. 13.Best estimate of 815 + 315? (a) 900 (b) 1100 (c) 1300
  14. 14.Best estimate of 607 + 847? (a) 1200 (b) 1400 (c) 1600
  15. 15.Best estimate of 26 × 14? (a) 300 (b) 3000 (c) 30
  16. 16.Best estimate of 21 × 58? (a) 1200 (b) 120 (c) 12000
  17. 17.Best estimate of 71 × 66? (a) 49000 (b) 4900 (c) 490
  18. 18.Best estimate of 96 × 82? (a) 8000 (b) 800 (c) 80000
  19. 19.Best estimate of 98 × 29? (a) 3000 (b) 30000 (c) 300
  20. 20.Best estimate of 302 + 713? (a) 1200 (b) 1000 (c) 800
  21. 21.Best estimate of 29 × 36? (a) 120 (b) 12000 (c) 1200
  22. 22.Best estimate of 18 × 32? (a) 600 (b) 6000 (c) 60
  23. 23.Best estimate of 565 + 799? (a) 1200 (b) 1600 (c) 1400
  24. 24.Best estimate of 551 + 699? (a) 1300 (b) 1500 (c) 1100
  25. 25.Best estimate of 78 × 91? (a) 72000 (b) 720 (c) 7200
  26. 26.Best estimate of 90 × 61? (a) 540 (b) 54000 (c) 5400
  27. 27.Best estimate of 814 + 239? (a) 1000 (b) 1200 (c) 800
  28. 28.Best estimate of 36 × 96? (a) 4000 (b) 400 (c) 40000
  29. 29.Best estimate of 26 × 69? (a) 210 (b) 2100 (c) 21000
  30. 30.Best estimate of 127 + 319? (a) 400 (b) 200 (c) 600
  31. 31.Best estimate of 18 × 30? (a) 60 (b) 6000 (c) 600
  32. 32.Best estimate of 96 × 47? (a) 50000 (b) 500 (c) 5000
  33. 33.Best estimate of 28 × 36? (a) 12000 (b) 1200 (c) 120
  34. 34.Best estimate of 16 × 51? (a) 10000 (b) 1000 (c) 100
  35. 35.Best estimate of 37 × 20? (a) 80 (b) 800 (c) 8000
  36. 36.Best estimate of 48 × 51? (a) 250 (b) 2500 (c) 25000
  37. 37.Best estimate of 483 + 619? (a) 1300 (b) 1100 (c) 900
  38. 38.Best estimate of 247 + 135? (a) 100 (b) 300 (c) 500
  39. 39.Best estimate of 232 + 733? (a) 1100 (b) 900 (c) 700
  40. 40.Best estimate of 784 + 415? (a) 1400 (b) 1200 (c) 1000

Answer key

  1. 1600
  2. 6300
  3. 1100
  4. 800
  5. 2400
  6. 1400
  7. 1800
  8. 800
  9. 4200
  10. 900
  11. 1200
  12. 2400
  13. 1100
  14. 1400
  15. 300
  16. 1200
  17. 4900
  18. 8000
  19. 3000
  20. 1000
  21. 1200
  22. 600
  23. 1400
  24. 1300
  25. 7200
  26. 5400
  27. 1000
  28. 4000
  29. 2100
  30. 400
  31. 600
  32. 5000
  33. 1200
  34. 1000
  35. 800
  36. 2500
  37. 1100
  38. 300
  39. 900
  40. 1200

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