← Rounding off and best estimate lesson New set →

Rounding Off and Estimation Worksheet

Mental maths lesson 15: Rounding off and best estimate · Set 622 · 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 151 + 653? (a) 1100 (b) 700 (c) 900
  2. 2.Best estimate of 49 × 76? (a) 400 (b) 40000 (c) 4000
  3. 3.Best estimate of 20 × 42? (a) 800 (b) 8000 (c) 80
  4. 4.Best estimate of 244 + 818? (a) 1200 (b) 1000 (c) 800
  5. 5.Best estimate of 751 + 237? (a) 800 (b) 1200 (c) 1000
  6. 6.Best estimate of 247 + 865? (a) 1300 (b) 1100 (c) 900
  7. 7.Best estimate of 499 + 806? (a) 1300 (b) 1500 (c) 1100
  8. 8.Best estimate of 575 + 444? (a) 800 (b) 1000 (c) 1200
  9. 9.Best estimate of 62 × 21? (a) 1200 (b) 12000 (c) 120
  10. 10.Best estimate of 515 + 748? (a) 1000 (b) 1400 (c) 1200
  11. 11.Best estimate of 16 × 12? (a) 200 (b) 20 (c) 2000
  12. 12.Best estimate of 56 × 41? (a) 24000 (b) 2400 (c) 240
  13. 13.Best estimate of 74 × 50? (a) 35000 (b) 350 (c) 3500
  14. 14.Best estimate of 26 × 31? (a) 90 (b) 900 (c) 9000
  15. 15.Best estimate of 19 × 62? (a) 12000 (b) 1200 (c) 120
  16. 16.Best estimate of 66 × 12? (a) 70 (b) 7000 (c) 700
  17. 17.Best estimate of 56 × 49? (a) 3000 (b) 30000 (c) 300
  18. 18.Best estimate of 83 × 26? (a) 24000 (b) 240 (c) 2400
  19. 19.Best estimate of 12 × 46? (a) 5000 (b) 500 (c) 50
  20. 20.Best estimate of 688 + 314? (a) 1200 (b) 1000 (c) 800
  21. 21.Best estimate of 538 + 274? (a) 800 (b) 600 (c) 1000
  22. 22.Best estimate of 92 × 60? (a) 54000 (b) 540 (c) 5400
  23. 23.Best estimate of 761 + 683? (a) 1300 (b) 1500 (c) 1700
  24. 24.Best estimate of 31 × 58? (a) 1800 (b) 18000 (c) 180
  25. 25.Best estimate of 283 + 312? (a) 800 (b) 400 (c) 600
  26. 26.Best estimate of 64 × 97? (a) 600 (b) 6000 (c) 60000
  27. 27.Best estimate of 251 + 189? (a) 500 (b) 300 (c) 700
  28. 28.Best estimate of 58 × 90? (a) 5400 (b) 540 (c) 54000
  29. 29.Best estimate of 33 × 76? (a) 240 (b) 24000 (c) 2400
  30. 30.Best estimate of 69 × 58? (a) 4200 (b) 42000 (c) 420
  31. 31.Best estimate of 254 + 231? (a) 300 (b) 700 (c) 500
  32. 32.Best estimate of 198 + 362? (a) 800 (b) 600 (c) 400
  33. 33.Best estimate of 22 × 67? (a) 1400 (b) 140 (c) 14000
  34. 34.Best estimate of 16 × 64? (a) 1200 (b) 120 (c) 12000
  35. 35.Best estimate of 80 × 27? (a) 24000 (b) 240 (c) 2400
  36. 36.Best estimate of 51 × 76? (a) 4000 (b) 40000 (c) 400
  37. 37.Best estimate of 508 + 348? (a) 1000 (b) 600 (c) 800
  38. 38.Best estimate of 26 × 89? (a) 2700 (b) 270 (c) 27000
  39. 39.Best estimate of 187 + 691? (a) 1100 (b) 700 (c) 900
  40. 40.Best estimate of 777 + 851? (a) 1500 (b) 1900 (c) 1700

Answer key

  1. 900
  2. 4000
  3. 800
  4. 1000
  5. 1000
  6. 1100
  7. 1300
  8. 1000
  9. 1200
  10. 1200
  11. 200
  12. 2400
  13. 3500
  14. 900
  15. 1200
  16. 700
  17. 3000
  18. 2400
  19. 500
  20. 1000
  21. 800
  22. 5400
  23. 1500
  24. 1800
  25. 600
  26. 6000
  27. 500
  28. 5400
  29. 2400
  30. 4200
  31. 500
  32. 600
  33. 1400
  34. 1200
  35. 2400
  36. 4000
  37. 800
  38. 2700
  39. 900
  40. 1700

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