← Rounding off and best estimate lesson New set →

Rounding Off and Estimation Worksheet

Mental maths lesson 15: Rounding off and best estimate · Set 175 · 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 84 × 72? (a) 5600 (b) 560 (c) 56000
  2. 2.Best estimate of 89 × 47? (a) 45000 (b) 4500 (c) 450
  3. 3.Best estimate of 748 + 420? (a) 900 (b) 1300 (c) 1100
  4. 4.Best estimate of 174 + 357? (a) 600 (b) 400 (c) 800
  5. 5.Best estimate of 21 × 41? (a) 80 (b) 8000 (c) 800
  6. 6.Best estimate of 56 × 12? (a) 6000 (b) 60 (c) 600
  7. 7.Best estimate of 13 × 39? (a) 4000 (b) 40 (c) 400
  8. 8.Best estimate of 12 × 36? (a) 4000 (b) 400 (c) 40
  9. 9.Best estimate of 91 × 66? (a) 63000 (b) 6300 (c) 630
  10. 10.Best estimate of 78 × 51? (a) 400 (b) 40000 (c) 4000
  11. 11.Best estimate of 97 × 24? (a) 200 (b) 2000 (c) 20000
  12. 12.Best estimate of 613 + 293? (a) 1100 (b) 700 (c) 900
  13. 13.Best estimate of 169 + 862? (a) 1100 (b) 1300 (c) 900
  14. 14.Best estimate of 72 × 12? (a) 7000 (b) 700 (c) 70
  15. 15.Best estimate of 68 × 70? (a) 490 (b) 49000 (c) 4900
  16. 16.Best estimate of 46 × 23? (a) 1000 (b) 100 (c) 10000
  17. 17.Best estimate of 718 + 275? (a) 1000 (b) 1200 (c) 800
  18. 18.Best estimate of 82 × 64? (a) 48000 (b) 4800 (c) 480
  19. 19.Best estimate of 52 × 12? (a) 5000 (b) 50 (c) 500
  20. 20.Best estimate of 418 + 666? (a) 1100 (b) 900 (c) 1300
  21. 21.Best estimate of 59 × 80? (a) 4800 (b) 480 (c) 48000
  22. 22.Best estimate of 137 + 500? (a) 800 (b) 600 (c) 400
  23. 23.Best estimate of 326 + 269? (a) 800 (b) 400 (c) 600
  24. 24.Best estimate of 58 × 81? (a) 480 (b) 4800 (c) 48000
  25. 25.Best estimate of 755 + 421? (a) 1200 (b) 1000 (c) 1400
  26. 26.Best estimate of 58 × 83? (a) 4800 (b) 48000 (c) 480
  27. 27.Best estimate of 831 + 449? (a) 1000 (b) 1200 (c) 1400
  28. 28.Best estimate of 674 + 859? (a) 1800 (b) 1600 (c) 1400
  29. 29.Best estimate of 620 + 595? (a) 1000 (b) 1200 (c) 1400
  30. 30.Best estimate of 567 + 485? (a) 900 (b) 1300 (c) 1100
  31. 31.Best estimate of 721 + 125? (a) 1000 (b) 600 (c) 800
  32. 32.Best estimate of 213 + 123? (a) 500 (b) 100 (c) 300
  33. 33.Best estimate of 90 × 24? (a) 1800 (b) 18000 (c) 180
  34. 34.Best estimate of 27 × 87? (a) 2700 (b) 27000 (c) 270
  35. 35.Best estimate of 53 × 16? (a) 1000 (b) 100 (c) 10000
  36. 36.Best estimate of 70 × 69? (a) 490 (b) 49000 (c) 4900
  37. 37.Best estimate of 12 × 44? (a) 4000 (b) 40 (c) 400
  38. 38.Best estimate of 737 + 470? (a) 1200 (b) 1000 (c) 1400
  39. 39.Best estimate of 73 × 89? (a) 63000 (b) 6300 (c) 630
  40. 40.Best estimate of 18 × 20? (a) 4000 (b) 400 (c) 40

Answer key

  1. 5600
  2. 4500
  3. 1100
  4. 600
  5. 800
  6. 600
  7. 400
  8. 400
  9. 6300
  10. 4000
  11. 2000
  12. 900
  13. 1100
  14. 700
  15. 4900
  16. 1000
  17. 1000
  18. 4800
  19. 500
  20. 1100
  21. 4800
  22. 600
  23. 600
  24. 4800
  25. 1200
  26. 4800
  27. 1200
  28. 1600
  29. 1200
  30. 1100
  31. 800
  32. 300
  33. 1800
  34. 2700
  35. 1000
  36. 4900
  37. 400
  38. 1200
  39. 6300
  40. 400

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