← Rounding off and best estimate lesson New set →

Rounding Off and Estimation Worksheet

Mental maths lesson 15: Rounding off and best estimate · Set 687 · 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 50 × 94? (a) 4500 (b) 45000 (c) 450
  2. 2.Best estimate of 213 + 818? (a) 1000 (b) 800 (c) 1200
  3. 3.Best estimate of 132 + 819? (a) 1100 (b) 900 (c) 700
  4. 4.Best estimate of 34 × 54? (a) 1500 (b) 15000 (c) 150
  5. 5.Best estimate of 794 + 860? (a) 1700 (b) 1900 (c) 1500
  6. 6.Best estimate of 449 + 845? (a) 1400 (b) 1000 (c) 1200
  7. 7.Best estimate of 331 + 154? (a) 500 (b) 300 (c) 700
  8. 8.Best estimate of 67 × 88? (a) 630 (b) 6300 (c) 63000
  9. 9.Best estimate of 73 × 89? (a) 630 (b) 6300 (c) 63000
  10. 10.Best estimate of 66 × 96? (a) 7000 (b) 70000 (c) 700
  11. 11.Best estimate of 537 + 593? (a) 1300 (b) 1100 (c) 900
  12. 12.Best estimate of 293 + 303? (a) 600 (b) 800 (c) 400
  13. 13.Best estimate of 67 × 46? (a) 35000 (b) 350 (c) 3500
  14. 14.Best estimate of 169 + 156? (a) 400 (b) 600 (c) 200
  15. 15.Best estimate of 39 × 40? (a) 16000 (b) 160 (c) 1600
  16. 16.Best estimate of 57 × 79? (a) 480 (b) 48000 (c) 4800
  17. 17.Best estimate of 46 × 47? (a) 250 (b) 2500 (c) 25000
  18. 18.Best estimate of 640 + 683? (a) 1500 (b) 1300 (c) 1100
  19. 19.Best estimate of 263 + 251? (a) 400 (b) 800 (c) 600
  20. 20.Best estimate of 696 + 747? (a) 1200 (b) 1400 (c) 1600
  21. 21.Best estimate of 497 + 314? (a) 800 (b) 1000 (c) 600
  22. 22.Best estimate of 94 × 44? (a) 3600 (b) 360 (c) 36000
  23. 23.Best estimate of 48 × 54? (a) 250 (b) 25000 (c) 2500
  24. 24.Best estimate of 54 × 31? (a) 1500 (b) 150 (c) 15000
  25. 25.Best estimate of 275 + 388? (a) 900 (b) 700 (c) 500
  26. 26.Best estimate of 871 + 728? (a) 1400 (b) 1600 (c) 1800
  27. 27.Best estimate of 626 + 777? (a) 1400 (b) 1600 (c) 1200
  28. 28.Best estimate of 146 + 520? (a) 400 (b) 800 (c) 600
  29. 29.Best estimate of 283 + 148? (a) 400 (b) 600 (c) 200
  30. 30.Best estimate of 69 × 92? (a) 63000 (b) 630 (c) 6300
  31. 31.Best estimate of 290 + 797? (a) 1300 (b) 900 (c) 1100
  32. 32.Best estimate of 758 + 692? (a) 1700 (b) 1500 (c) 1300
  33. 33.Best estimate of 89 × 51? (a) 450 (b) 45000 (c) 4500
  34. 34.Best estimate of 473 + 253? (a) 800 (b) 1000 (c) 600
  35. 35.Best estimate of 20 × 27? (a) 6000 (b) 60 (c) 600
  36. 36.Best estimate of 31 × 60? (a) 180 (b) 1800 (c) 18000
  37. 37.Best estimate of 459 + 732? (a) 1400 (b) 1000 (c) 1200
  38. 38.Best estimate of 14 × 96? (a) 10000 (b) 100 (c) 1000
  39. 39.Best estimate of 574 + 132? (a) 700 (b) 900 (c) 500
  40. 40.Best estimate of 20 × 43? (a) 8000 (b) 800 (c) 80

Answer key

  1. 4500
  2. 1000
  3. 900
  4. 1500
  5. 1700
  6. 1200
  7. 500
  8. 6300
  9. 6300
  10. 7000
  11. 1100
  12. 600
  13. 3500
  14. 400
  15. 1600
  16. 4800
  17. 2500
  18. 1300
  19. 600
  20. 1400
  21. 800
  22. 3600
  23. 2500
  24. 1500
  25. 700
  26. 1600
  27. 1400
  28. 600
  29. 400
  30. 6300
  31. 1100
  32. 1500
  33. 4500
  34. 800
  35. 600
  36. 1800
  37. 1200
  38. 1000
  39. 700
  40. 800

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