← Rounding off and best estimate lesson New set →

Rounding Off and Estimation Worksheet

Mental maths lesson 15: Rounding off and best estimate · Set 975 · 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 526 + 771? (a) 1500 (b) 1300 (c) 1100
  2. 2.Best estimate of 13 × 72? (a) 700 (b) 70 (c) 7000
  3. 3.Best estimate of 572 + 878? (a) 1700 (b) 1500 (c) 1300
  4. 4.Best estimate of 86 × 41? (a) 36000 (b) 3600 (c) 360
  5. 5.Best estimate of 77 × 34? (a) 2400 (b) 24000 (c) 240
  6. 6.Best estimate of 321 + 309? (a) 800 (b) 400 (c) 600
  7. 7.Best estimate of 91 × 27? (a) 270 (b) 27000 (c) 2700
  8. 8.Best estimate of 249 + 441? (a) 600 (b) 800 (c) 400
  9. 9.Best estimate of 691 + 133? (a) 800 (b) 1000 (c) 600
  10. 10.Best estimate of 66 × 28? (a) 2100 (b) 21000 (c) 210
  11. 11.Best estimate of 178 + 846? (a) 800 (b) 1000 (c) 1200
  12. 12.Best estimate of 28 × 71? (a) 210 (b) 21000 (c) 2100
  13. 13.Best estimate of 64 × 19? (a) 1200 (b) 12000 (c) 120
  14. 14.Best estimate of 642 + 538? (a) 1100 (b) 900 (c) 1300
  15. 15.Best estimate of 63 × 50? (a) 3000 (b) 300 (c) 30000
  16. 16.Best estimate of 36 × 13? (a) 400 (b) 4000 (c) 40
  17. 17.Best estimate of 96 × 88? (a) 900 (b) 9000 (c) 90000
  18. 18.Best estimate of 836 + 120? (a) 900 (b) 700 (c) 1100
  19. 19.Best estimate of 66 × 92? (a) 6300 (b) 63000 (c) 630
  20. 20.Best estimate of 825 + 622? (a) 1400 (b) 1200 (c) 1600
  21. 21.Best estimate of 311 + 515? (a) 800 (b) 600 (c) 1000
  22. 22.Best estimate of 357 + 586? (a) 1000 (b) 1200 (c) 800
  23. 23.Best estimate of 487 + 309? (a) 800 (b) 600 (c) 1000
  24. 24.Best estimate of 373 + 744? (a) 1300 (b) 900 (c) 1100
  25. 25.Best estimate of 135 + 236? (a) 300 (b) 100 (c) 500
  26. 26.Best estimate of 236 + 592? (a) 1000 (b) 600 (c) 800
  27. 27.Best estimate of 82 × 43? (a) 3200 (b) 320 (c) 32000
  28. 28.Best estimate of 484 + 382? (a) 1100 (b) 700 (c) 900
  29. 29.Best estimate of 30 × 49? (a) 1500 (b) 150 (c) 15000
  30. 30.Best estimate of 61 × 79? (a) 4800 (b) 480 (c) 48000
  31. 31.Best estimate of 38 × 49? (a) 2000 (b) 20000 (c) 200
  32. 32.Best estimate of 500 + 720? (a) 1400 (b) 1000 (c) 1200
  33. 33.Best estimate of 83 × 74? (a) 56000 (b) 560 (c) 5600
  34. 34.Best estimate of 46 × 46? (a) 250 (b) 2500 (c) 25000
  35. 35.Best estimate of 60 × 16? (a) 1200 (b) 12000 (c) 120
  36. 36.Best estimate of 352 + 875? (a) 1300 (b) 1500 (c) 1100
  37. 37.Best estimate of 96 × 94? (a) 9000 (b) 90000 (c) 900
  38. 38.Best estimate of 253 + 188? (a) 700 (b) 500 (c) 300
  39. 39.Best estimate of 58 × 79? (a) 4800 (b) 480 (c) 48000
  40. 40.Best estimate of 56 × 76? (a) 4800 (b) 48000 (c) 480

Answer key

  1. 1300
  2. 700
  3. 1500
  4. 3600
  5. 2400
  6. 600
  7. 2700
  8. 600
  9. 800
  10. 2100
  11. 1000
  12. 2100
  13. 1200
  14. 1100
  15. 3000
  16. 400
  17. 9000
  18. 900
  19. 6300
  20. 1400
  21. 800
  22. 1000
  23. 800
  24. 1100
  25. 300
  26. 800
  27. 3200
  28. 900
  29. 1500
  30. 4800
  31. 2000
  32. 1200
  33. 5600
  34. 2500
  35. 1200
  36. 1300
  37. 9000
  38. 500
  39. 4800
  40. 4800

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