← Rounding off and best estimate lesson New set →

Rounding Off and Estimation Worksheet

Mental maths lesson 15: Rounding off and best estimate · Set 195 · 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 86 × 32? (a) 270 (b) 27000 (c) 2700
  2. 2.Best estimate of 526 + 580? (a) 1100 (b) 900 (c) 1300
  3. 3.Best estimate of 192 + 619? (a) 600 (b) 1000 (c) 800
  4. 4.Best estimate of 343 + 296? (a) 400 (b) 800 (c) 600
  5. 5.Best estimate of 62 × 46? (a) 30000 (b) 300 (c) 3000
  6. 6.Best estimate of 689 + 740? (a) 1600 (b) 1200 (c) 1400
  7. 7.Best estimate of 41 × 16? (a) 800 (b) 80 (c) 8000
  8. 8.Best estimate of 610 + 195? (a) 800 (b) 1000 (c) 600
  9. 9.Best estimate of 129 + 651? (a) 800 (b) 600 (c) 1000
  10. 10.Best estimate of 697 + 401? (a) 1100 (b) 1300 (c) 900
  11. 11.Best estimate of 59 × 27? (a) 1800 (b) 180 (c) 18000
  12. 12.Best estimate of 46 × 94? (a) 450 (b) 4500 (c) 45000
  13. 13.Best estimate of 16 × 84? (a) 1600 (b) 160 (c) 16000
  14. 14.Best estimate of 26 × 87? (a) 27000 (b) 270 (c) 2700
  15. 15.Best estimate of 76 × 93? (a) 72000 (b) 720 (c) 7200
  16. 16.Best estimate of 12 × 38? (a) 4000 (b) 400 (c) 40
  17. 17.Best estimate of 783 + 404? (a) 1000 (b) 1200 (c) 1400
  18. 18.Best estimate of 46 × 29? (a) 150 (b) 15000 (c) 1500
  19. 19.Best estimate of 93 × 86? (a) 81000 (b) 810 (c) 8100
  20. 20.Best estimate of 833 + 808? (a) 1800 (b) 1600 (c) 1400
  21. 21.Best estimate of 648 + 661? (a) 1300 (b) 1500 (c) 1100
  22. 22.Best estimate of 46 × 74? (a) 35000 (b) 350 (c) 3500
  23. 23.Best estimate of 83 × 16? (a) 1600 (b) 16000 (c) 160
  24. 24.Best estimate of 36 × 20? (a) 80 (b) 800 (c) 8000
  25. 25.Best estimate of 40 × 51? (a) 200 (b) 2000 (c) 20000
  26. 26.Best estimate of 42 × 29? (a) 12000 (b) 120 (c) 1200
  27. 27.Best estimate of 20 × 16? (a) 400 (b) 4000 (c) 40
  28. 28.Best estimate of 38 × 51? (a) 200 (b) 20000 (c) 2000
  29. 29.Best estimate of 56 × 38? (a) 2400 (b) 24000 (c) 240
  30. 30.Best estimate of 555 + 566? (a) 1400 (b) 1000 (c) 1200
  31. 31.Best estimate of 19 × 16? (a) 400 (b) 40 (c) 4000
  32. 32.Best estimate of 808 + 642? (a) 1600 (b) 1200 (c) 1400
  33. 33.Best estimate of 49 × 96? (a) 50000 (b) 500 (c) 5000
  34. 34.Best estimate of 629 + 252? (a) 700 (b) 1100 (c) 900
  35. 35.Best estimate of 44 × 32? (a) 12000 (b) 1200 (c) 120
  36. 36.Best estimate of 96 × 72? (a) 7000 (b) 70000 (c) 700
  37. 37.Best estimate of 88 × 98? (a) 90000 (b) 9000 (c) 900
  38. 38.Best estimate of 19 × 36? (a) 8000 (b) 800 (c) 80
  39. 39.Best estimate of 221 + 488? (a) 700 (b) 900 (c) 500
  40. 40.Best estimate of 13 × 38? (a) 400 (b) 4000 (c) 40

Answer key

  1. 2700
  2. 1100
  3. 800
  4. 600
  5. 3000
  6. 1400
  7. 800
  8. 800
  9. 800
  10. 1100
  11. 1800
  12. 4500
  13. 1600
  14. 2700
  15. 7200
  16. 400
  17. 1200
  18. 1500
  19. 8100
  20. 1600
  21. 1300
  22. 3500
  23. 1600
  24. 800
  25. 2000
  26. 1200
  27. 400
  28. 2000
  29. 2400
  30. 1200
  31. 400
  32. 1400
  33. 5000
  34. 900
  35. 1200
  36. 7000
  37. 9000
  38. 800
  39. 700
  40. 400

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