← Rounding off and best estimate lesson New set →

Rounding Off and Estimation Worksheet

Mental maths lesson 15: Rounding off and best estimate · Set 553 · 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 79 × 56? (a) 4800 (b) 48000 (c) 480
  2. 2.Best estimate of 91 × 43? (a) 3600 (b) 360 (c) 36000
  3. 3.Best estimate of 97 × 48? (a) 500 (b) 5000 (c) 50000
  4. 4.Best estimate of 56 × 98? (a) 60000 (b) 600 (c) 6000
  5. 5.Best estimate of 58 × 84? (a) 48000 (b) 4800 (c) 480
  6. 6.Best estimate of 83 × 90? (a) 7200 (b) 720 (c) 72000
  7. 7.Best estimate of 52 × 50? (a) 25000 (b) 2500 (c) 250
  8. 8.Best estimate of 532 + 237? (a) 900 (b) 500 (c) 700
  9. 9.Best estimate of 59 × 68? (a) 420 (b) 4200 (c) 42000
  10. 10.Best estimate of 47 × 76? (a) 4000 (b) 400 (c) 40000
  11. 11.Best estimate of 406 + 744? (a) 900 (b) 1100 (c) 1300
  12. 12.Best estimate of 83 × 68? (a) 560 (b) 5600 (c) 56000
  13. 13.Best estimate of 42 × 92? (a) 36000 (b) 3600 (c) 360
  14. 14.Best estimate of 70 × 19? (a) 140 (b) 1400 (c) 14000
  15. 15.Best estimate of 574 + 700? (a) 1100 (b) 1300 (c) 1500
  16. 16.Best estimate of 70 × 52? (a) 35000 (b) 3500 (c) 350
  17. 17.Best estimate of 17 × 36? (a) 80 (b) 800 (c) 8000
  18. 18.Best estimate of 42 × 48? (a) 20000 (b) 2000 (c) 200
  19. 19.Best estimate of 868 + 793? (a) 1700 (b) 1900 (c) 1500
  20. 20.Best estimate of 679 + 661? (a) 1600 (b) 1400 (c) 1200
  21. 21.Best estimate of 287 + 324? (a) 800 (b) 600 (c) 400
  22. 22.Best estimate of 872 + 389? (a) 1300 (b) 1100 (c) 1500
  23. 23.Best estimate of 171 + 183? (a) 200 (b) 600 (c) 400
  24. 24.Best estimate of 147 + 660? (a) 600 (b) 1000 (c) 800
  25. 25.Best estimate of 519 + 477? (a) 1000 (b) 800 (c) 1200
  26. 26.Best estimate of 83 × 16? (a) 16000 (b) 1600 (c) 160
  27. 27.Best estimate of 71 × 41? (a) 280 (b) 2800 (c) 28000
  28. 28.Best estimate of 28 × 51? (a) 1500 (b) 15000 (c) 150
  29. 29.Best estimate of 172 + 230? (a) 400 (b) 600 (c) 200
  30. 30.Best estimate of 871 + 469? (a) 1600 (b) 1200 (c) 1400
  31. 31.Best estimate of 636 + 807? (a) 1400 (b) 1600 (c) 1200
  32. 32.Best estimate of 244 + 722? (a) 1100 (b) 700 (c) 900
  33. 33.Best estimate of 97 × 16? (a) 2000 (b) 200 (c) 20000
  34. 34.Best estimate of 91 × 88? (a) 8100 (b) 81000 (c) 810
  35. 35.Best estimate of 36 × 97? (a) 40000 (b) 400 (c) 4000
  36. 36.Best estimate of 709 + 159? (a) 700 (b) 1100 (c) 900
  37. 37.Best estimate of 12 × 97? (a) 10000 (b) 100 (c) 1000
  38. 38.Best estimate of 804 + 847? (a) 1800 (b) 1600 (c) 1400
  39. 39.Best estimate of 61 × 58? (a) 360 (b) 3600 (c) 36000
  40. 40.Best estimate of 71 × 66? (a) 49000 (b) 490 (c) 4900

Answer key

  1. 4800
  2. 3600
  3. 5000
  4. 6000
  5. 4800
  6. 7200
  7. 2500
  8. 700
  9. 4200
  10. 4000
  11. 1100
  12. 5600
  13. 3600
  14. 1400
  15. 1300
  16. 3500
  17. 800
  18. 2000
  19. 1700
  20. 1400
  21. 600
  22. 1300
  23. 400
  24. 800
  25. 1000
  26. 1600
  27. 2800
  28. 1500
  29. 400
  30. 1400
  31. 1400
  32. 900
  33. 2000
  34. 8100
  35. 4000
  36. 900
  37. 1000
  38. 1600
  39. 3600
  40. 4900

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