← Rounding off and best estimate lesson New set →

Rounding Off and Estimation Worksheet

Mental maths lesson 15: Rounding off and best estimate · Set 865 · 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 528 + 748? (a) 1000 (b) 1400 (c) 1200
  2. 2.Best estimate of 17 × 71? (a) 140 (b) 1400 (c) 14000
  3. 3.Best estimate of 31 × 76? (a) 2400 (b) 24000 (c) 240
  4. 4.Best estimate of 574 + 331? (a) 1100 (b) 900 (c) 700
  5. 5.Best estimate of 93 × 67? (a) 63000 (b) 630 (c) 6300
  6. 6.Best estimate of 84 × 16? (a) 1600 (b) 16000 (c) 160
  7. 7.Best estimate of 659 + 282? (a) 1200 (b) 800 (c) 1000
  8. 8.Best estimate of 56 × 28? (a) 18000 (b) 1800 (c) 180
  9. 9.Best estimate of 800 + 216? (a) 1200 (b) 800 (c) 1000
  10. 10.Best estimate of 872 + 466? (a) 1600 (b) 1400 (c) 1200
  11. 11.Best estimate of 24 × 81? (a) 1600 (b) 160 (c) 16000
  12. 12.Best estimate of 645 + 670? (a) 1500 (b) 1300 (c) 1100
  13. 13.Best estimate of 20 × 23? (a) 40 (b) 400 (c) 4000
  14. 14.Best estimate of 37 × 88? (a) 3600 (b) 360 (c) 36000
  15. 15.Best estimate of 56 × 46? (a) 3000 (b) 300 (c) 30000
  16. 16.Best estimate of 591 + 530? (a) 900 (b) 1100 (c) 1300
  17. 17.Best estimate of 32 × 62? (a) 18000 (b) 1800 (c) 180
  18. 18.Best estimate of 92 × 54? (a) 4500 (b) 45000 (c) 450
  19. 19.Best estimate of 374 + 304? (a) 500 (b) 900 (c) 700
  20. 20.Best estimate of 265 + 657? (a) 800 (b) 1200 (c) 1000
  21. 21.Best estimate of 625 + 179? (a) 800 (b) 1000 (c) 600
  22. 22.Best estimate of 76 × 91? (a) 72000 (b) 7200 (c) 720
  23. 23.Best estimate of 136 + 868? (a) 800 (b) 1000 (c) 1200
  24. 24.Best estimate of 82 × 24? (a) 1600 (b) 160 (c) 16000
  25. 25.Best estimate of 175 + 435? (a) 600 (b) 400 (c) 800
  26. 26.Best estimate of 24 × 16? (a) 4000 (b) 40 (c) 400
  27. 27.Best estimate of 36 × 33? (a) 1200 (b) 12000 (c) 120
  28. 28.Best estimate of 233 + 640? (a) 1000 (b) 800 (c) 600
  29. 29.Best estimate of 37 × 63? (a) 2400 (b) 240 (c) 24000
  30. 30.Best estimate of 182 + 345? (a) 300 (b) 500 (c) 700
  31. 31.Best estimate of 18 × 32? (a) 600 (b) 60 (c) 6000
  32. 32.Best estimate of 41 × 57? (a) 24000 (b) 240 (c) 2400
  33. 33.Best estimate of 17 × 89? (a) 1800 (b) 180 (c) 18000
  34. 34.Best estimate of 638 + 239? (a) 1000 (b) 800 (c) 600
  35. 35.Best estimate of 60 × 81? (a) 48000 (b) 480 (c) 4800
  36. 36.Best estimate of 56 × 17? (a) 120 (b) 12000 (c) 1200
  37. 37.Best estimate of 164 + 325? (a) 700 (b) 500 (c) 300
  38. 38.Best estimate of 524 + 806? (a) 1100 (b) 1500 (c) 1300
  39. 39.Best estimate of 96 × 59? (a) 60000 (b) 600 (c) 6000
  40. 40.Best estimate of 217 + 290? (a) 500 (b) 300 (c) 700

Answer key

  1. 1200
  2. 1400
  3. 2400
  4. 900
  5. 6300
  6. 1600
  7. 1000
  8. 1800
  9. 1000
  10. 1400
  11. 1600
  12. 1300
  13. 400
  14. 3600
  15. 3000
  16. 1100
  17. 1800
  18. 4500
  19. 700
  20. 1000
  21. 800
  22. 7200
  23. 1000
  24. 1600
  25. 600
  26. 400
  27. 1200
  28. 800
  29. 2400
  30. 500
  31. 600
  32. 2400
  33. 1800
  34. 800
  35. 4800
  36. 1200
  37. 500
  38. 1300
  39. 6000
  40. 500

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