← Rounding off and best estimate lesson New set →

Rounding Off and Estimation Worksheet

Mental maths lesson 15: Rounding off and best estimate · Set 167 · 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 58 × 41? (a) 24000 (b) 2400 (c) 240
  2. 2.Best estimate of 81 × 86? (a) 72000 (b) 720 (c) 7200
  3. 3.Best estimate of 205 + 717? (a) 1100 (b) 700 (c) 900
  4. 4.Best estimate of 659 + 246? (a) 900 (b) 700 (c) 1100
  5. 5.Best estimate of 68 × 27? (a) 2100 (b) 210 (c) 21000
  6. 6.Best estimate of 547 + 867? (a) 1400 (b) 1200 (c) 1600
  7. 7.Best estimate of 775 + 713? (a) 1500 (b) 1700 (c) 1300
  8. 8.Best estimate of 757 + 673? (a) 1700 (b) 1500 (c) 1300
  9. 9.Best estimate of 81 × 23? (a) 160 (b) 1600 (c) 16000
  10. 10.Best estimate of 42 × 22? (a) 8000 (b) 80 (c) 800
  11. 11.Best estimate of 44 × 67? (a) 280 (b) 2800 (c) 28000
  12. 12.Best estimate of 873 + 800? (a) 1500 (b) 1700 (c) 1900
  13. 13.Best estimate of 41 × 54? (a) 2000 (b) 20000 (c) 200
  14. 14.Best estimate of 127 + 218? (a) 500 (b) 100 (c) 300
  15. 15.Best estimate of 354 + 505? (a) 700 (b) 1100 (c) 900
  16. 16.Best estimate of 77 × 91? (a) 720 (b) 72000 (c) 7200
  17. 17.Best estimate of 31 × 91? (a) 2700 (b) 27000 (c) 270
  18. 18.Best estimate of 574 + 257? (a) 900 (b) 700 (c) 1100
  19. 19.Best estimate of 53 × 41? (a) 200 (b) 20000 (c) 2000
  20. 20.Best estimate of 59 × 50? (a) 30000 (b) 300 (c) 3000
  21. 21.Best estimate of 68 × 33? (a) 210 (b) 2100 (c) 21000
  22. 22.Best estimate of 63 × 26? (a) 1800 (b) 180 (c) 18000
  23. 23.Best estimate of 78 × 33? (a) 2400 (b) 24000 (c) 240
  24. 24.Best estimate of 19 × 66? (a) 14000 (b) 1400 (c) 140
  25. 25.Best estimate of 17 × 13? (a) 200 (b) 2000 (c) 20
  26. 26.Best estimate of 260 + 814? (a) 1300 (b) 1100 (c) 900
  27. 27.Best estimate of 30 × 44? (a) 120 (b) 12000 (c) 1200
  28. 28.Best estimate of 498 + 852? (a) 1200 (b) 1400 (c) 1600
  29. 29.Best estimate of 749 + 451? (a) 1400 (b) 1000 (c) 1200
  30. 30.Best estimate of 19 × 54? (a) 10000 (b) 1000 (c) 100
  31. 31.Best estimate of 83 × 80? (a) 64000 (b) 6400 (c) 640
  32. 32.Best estimate of 158 + 337? (a) 500 (b) 300 (c) 700
  33. 33.Best estimate of 77 × 53? (a) 4000 (b) 400 (c) 40000
  34. 34.Best estimate of 580 + 255? (a) 900 (b) 700 (c) 1100
  35. 35.Best estimate of 369 + 467? (a) 1100 (b) 900 (c) 700
  36. 36.Best estimate of 36 × 33? (a) 12000 (b) 120 (c) 1200
  37. 37.Best estimate of 246 + 585? (a) 1000 (b) 600 (c) 800
  38. 38.Best estimate of 631 + 556? (a) 1400 (b) 1200 (c) 1000
  39. 39.Best estimate of 83 × 46? (a) 4000 (b) 40000 (c) 400
  40. 40.Best estimate of 193 + 182? (a) 400 (b) 200 (c) 600

Answer key

  1. 2400
  2. 7200
  3. 900
  4. 900
  5. 2100
  6. 1400
  7. 1500
  8. 1500
  9. 1600
  10. 800
  11. 2800
  12. 1700
  13. 2000
  14. 300
  15. 900
  16. 7200
  17. 2700
  18. 900
  19. 2000
  20. 3000
  21. 2100
  22. 1800
  23. 2400
  24. 1400
  25. 200
  26. 1100
  27. 1200
  28. 1400
  29. 1200
  30. 1000
  31. 6400
  32. 500
  33. 4000
  34. 900
  35. 900
  36. 1200
  37. 800
  38. 1200
  39. 4000
  40. 400

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