← Rounding off and best estimate lesson New set →

Rounding Off and Estimation Worksheet

Mental maths lesson 15: Rounding off and best estimate · Set 109 · 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 471 + 394? (a) 700 (b) 900 (c) 1100
  2. 2.Best estimate of 84 × 70? (a) 56000 (b) 5600 (c) 560
  3. 3.Best estimate of 34 × 36? (a) 1200 (b) 120 (c) 12000
  4. 4.Best estimate of 371 + 251? (a) 700 (b) 900 (c) 500
  5. 5.Best estimate of 387 + 665? (a) 900 (b) 1100 (c) 1300
  6. 6.Best estimate of 543 + 738? (a) 1000 (b) 1400 (c) 1200
  7. 7.Best estimate of 94 × 70? (a) 63000 (b) 6300 (c) 630
  8. 8.Best estimate of 92 × 37? (a) 3600 (b) 360 (c) 36000
  9. 9.Best estimate of 124 + 298? (a) 200 (b) 600 (c) 400
  10. 10.Best estimate of 127 + 340? (a) 400 (b) 600 (c) 200
  11. 11.Best estimate of 41 × 92? (a) 360 (b) 36000 (c) 3600
  12. 12.Best estimate of 76 × 41? (a) 32000 (b) 320 (c) 3200
  13. 13.Best estimate of 270 + 851? (a) 1000 (b) 1400 (c) 1200
  14. 14.Best estimate of 532 + 394? (a) 900 (b) 700 (c) 1100
  15. 15.Best estimate of 827 + 517? (a) 1300 (b) 1500 (c) 1100
  16. 16.Best estimate of 56 × 90? (a) 5400 (b) 54000 (c) 540
  17. 17.Best estimate of 161 + 586? (a) 1000 (b) 800 (c) 600
  18. 18.Best estimate of 93 × 92? (a) 81000 (b) 810 (c) 8100
  19. 19.Best estimate of 172 + 685? (a) 700 (b) 1100 (c) 900
  20. 20.Best estimate of 343 + 878? (a) 1200 (b) 1400 (c) 1000
  21. 21.Best estimate of 32 × 67? (a) 21000 (b) 210 (c) 2100
  22. 22.Best estimate of 656 + 493? (a) 1400 (b) 1200 (c) 1000
  23. 23.Best estimate of 122 + 583? (a) 700 (b) 500 (c) 900
  24. 24.Best estimate of 34 × 73? (a) 21000 (b) 2100 (c) 210
  25. 25.Best estimate of 82 × 23? (a) 16000 (b) 1600 (c) 160
  26. 26.Best estimate of 605 + 464? (a) 1300 (b) 1100 (c) 900
  27. 27.Best estimate of 205 + 137? (a) 100 (b) 500 (c) 300
  28. 28.Best estimate of 58 × 87? (a) 540 (b) 5400 (c) 54000
  29. 29.Best estimate of 879 + 652? (a) 1800 (b) 1400 (c) 1600
  30. 30.Best estimate of 787 + 263? (a) 1100 (b) 900 (c) 1300
  31. 31.Best estimate of 169 + 307? (a) 700 (b) 500 (c) 300
  32. 32.Best estimate of 530 + 642? (a) 1100 (b) 900 (c) 1300
  33. 33.Best estimate of 19 × 36? (a) 8000 (b) 80 (c) 800
  34. 34.Best estimate of 47 × 96? (a) 50000 (b) 500 (c) 5000
  35. 35.Best estimate of 14 × 64? (a) 6000 (b) 60 (c) 600
  36. 36.Best estimate of 54 × 66? (a) 350 (b) 3500 (c) 35000
  37. 37.Best estimate of 59 × 56? (a) 3600 (b) 36000 (c) 360
  38. 38.Best estimate of 469 + 486? (a) 1000 (b) 1200 (c) 800
  39. 39.Best estimate of 73 × 47? (a) 35000 (b) 350 (c) 3500
  40. 40.Best estimate of 59 × 46? (a) 30000 (b) 3000 (c) 300

Answer key

  1. 900
  2. 5600
  3. 1200
  4. 700
  5. 1100
  6. 1200
  7. 6300
  8. 3600
  9. 400
  10. 400
  11. 3600
  12. 3200
  13. 1200
  14. 900
  15. 1300
  16. 5400
  17. 800
  18. 8100
  19. 900
  20. 1200
  21. 2100
  22. 1200
  23. 700
  24. 2100
  25. 1600
  26. 1100
  27. 300
  28. 5400
  29. 1600
  30. 1100
  31. 500
  32. 1100
  33. 800
  34. 5000
  35. 600
  36. 3500
  37. 3600
  38. 1000
  39. 3500
  40. 3000

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