← Rounding off and best estimate lesson New set →

Rounding Off and Estimation Worksheet

Mental maths lesson 15: Rounding off and best estimate · Set 861 · 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 89 × 60? (a) 5400 (b) 54000 (c) 540
  2. 2.Best estimate of 18 × 43? (a) 8000 (b) 80 (c) 800
  3. 3.Best estimate of 67 × 40? (a) 28000 (b) 280 (c) 2800
  4. 4.Best estimate of 847 + 785? (a) 1800 (b) 1600 (c) 1400
  5. 5.Best estimate of 38 × 90? (a) 36000 (b) 3600 (c) 360
  6. 6.Best estimate of 633 + 299? (a) 1100 (b) 700 (c) 900
  7. 7.Best estimate of 291 + 180? (a) 500 (b) 700 (c) 300
  8. 8.Best estimate of 21 × 97? (a) 20000 (b) 2000 (c) 200
  9. 9.Best estimate of 34 × 54? (a) 15000 (b) 150 (c) 1500
  10. 10.Best estimate of 698 + 194? (a) 900 (b) 1100 (c) 700
  11. 11.Best estimate of 88 × 60? (a) 540 (b) 54000 (c) 5400
  12. 12.Best estimate of 200 + 554? (a) 1000 (b) 600 (c) 800
  13. 13.Best estimate of 59 × 72? (a) 4200 (b) 420 (c) 42000
  14. 14.Best estimate of 28 × 49? (a) 15000 (b) 1500 (c) 150
  15. 15.Best estimate of 51 × 30? (a) 15000 (b) 1500 (c) 150
  16. 16.Best estimate of 68 × 21? (a) 14000 (b) 1400 (c) 140
  17. 17.Best estimate of 646 + 307? (a) 900 (b) 700 (c) 1100
  18. 18.Best estimate of 789 + 130? (a) 900 (b) 1100 (c) 700
  19. 19.Best estimate of 13 × 39? (a) 400 (b) 4000 (c) 40
  20. 20.Best estimate of 351 + 207? (a) 600 (b) 800 (c) 400
  21. 21.Best estimate of 616 + 421? (a) 1200 (b) 800 (c) 1000
  22. 22.Best estimate of 19 × 67? (a) 1400 (b) 14000 (c) 140
  23. 23.Best estimate of 589 + 752? (a) 1400 (b) 1200 (c) 1600
  24. 24.Best estimate of 49 × 76? (a) 4000 (b) 40000 (c) 400
  25. 25.Best estimate of 12 × 32? (a) 30 (b) 3000 (c) 300
  26. 26.Best estimate of 50 × 36? (a) 20000 (b) 200 (c) 2000
  27. 27.Best estimate of 876 + 177? (a) 1300 (b) 1100 (c) 900
  28. 28.Best estimate of 62 × 64? (a) 3600 (b) 360 (c) 36000
  29. 29.Best estimate of 61 × 16? (a) 1200 (b) 12000 (c) 120
  30. 30.Best estimate of 60 × 83? (a) 4800 (b) 480 (c) 48000
  31. 31.Best estimate of 56 × 41? (a) 24000 (b) 240 (c) 2400
  32. 32.Best estimate of 36 × 29? (a) 12000 (b) 1200 (c) 120
  33. 33.Best estimate of 588 + 521? (a) 900 (b) 1300 (c) 1100
  34. 34.Best estimate of 86 × 86? (a) 81000 (b) 8100 (c) 810
  35. 35.Best estimate of 298 + 578? (a) 1100 (b) 700 (c) 900
  36. 36.Best estimate of 427 + 159? (a) 800 (b) 600 (c) 400
  37. 37.Best estimate of 63 × 44? (a) 24000 (b) 2400 (c) 240
  38. 38.Best estimate of 517 + 607? (a) 900 (b) 1300 (c) 1100
  39. 39.Best estimate of 225 + 852? (a) 1100 (b) 1300 (c) 900
  40. 40.Best estimate of 77 × 14? (a) 80 (b) 800 (c) 8000

Answer key

  1. 5400
  2. 800
  3. 2800
  4. 1600
  5. 3600
  6. 900
  7. 500
  8. 2000
  9. 1500
  10. 900
  11. 5400
  12. 800
  13. 4200
  14. 1500
  15. 1500
  16. 1400
  17. 900
  18. 900
  19. 400
  20. 600
  21. 1000
  22. 1400
  23. 1400
  24. 4000
  25. 300
  26. 2000
  27. 1100
  28. 3600
  29. 1200
  30. 4800
  31. 2400
  32. 1200
  33. 1100
  34. 8100
  35. 900
  36. 600
  37. 2400
  38. 1100
  39. 1100
  40. 800

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