← Rounding off and best estimate lesson New set →

Rounding Off and Estimation Worksheet

Mental maths lesson 15: Rounding off and best estimate · Set 676 · 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 479 + 539? (a) 1000 (b) 1200 (c) 800
  2. 2.Best estimate of 77 × 52? (a) 4000 (b) 40000 (c) 400
  3. 3.Best estimate of 22 × 80? (a) 160 (b) 1600 (c) 16000
  4. 4.Best estimate of 17 × 72? (a) 14000 (b) 140 (c) 1400
  5. 5.Best estimate of 73 × 62? (a) 420 (b) 4200 (c) 42000
  6. 6.Best estimate of 82 × 38? (a) 3200 (b) 320 (c) 32000
  7. 7.Best estimate of 279 + 728? (a) 1000 (b) 800 (c) 1200
  8. 8.Best estimate of 90 × 40? (a) 36000 (b) 3600 (c) 360
  9. 9.Best estimate of 456 + 318? (a) 600 (b) 800 (c) 1000
  10. 10.Best estimate of 542 + 330? (a) 600 (b) 800 (c) 1000
  11. 11.Best estimate of 28 × 86? (a) 2700 (b) 27000 (c) 270
  12. 12.Best estimate of 30 × 31? (a) 90 (b) 9000 (c) 900
  13. 13.Best estimate of 16 × 13? (a) 200 (b) 2000 (c) 20
  14. 14.Best estimate of 605 + 135? (a) 900 (b) 700 (c) 500
  15. 15.Best estimate of 16 × 60? (a) 1200 (b) 12000 (c) 120
  16. 16.Best estimate of 673 + 477? (a) 1000 (b) 1400 (c) 1200
  17. 17.Best estimate of 189 + 168? (a) 200 (b) 600 (c) 400
  18. 18.Best estimate of 30 × 22? (a) 6000 (b) 60 (c) 600
  19. 19.Best estimate of 748 + 466? (a) 1000 (b) 1400 (c) 1200
  20. 20.Best estimate of 685 + 561? (a) 1500 (b) 1100 (c) 1300
  21. 21.Best estimate of 60 × 76? (a) 4800 (b) 48000 (c) 480
  22. 22.Best estimate of 30 × 90? (a) 27000 (b) 270 (c) 2700
  23. 23.Best estimate of 356 + 862? (a) 1500 (b) 1300 (c) 1100
  24. 24.Best estimate of 52 × 86? (a) 45000 (b) 4500 (c) 450
  25. 25.Best estimate of 64 × 12? (a) 600 (b) 60 (c) 6000
  26. 26.Best estimate of 554 + 741? (a) 1500 (b) 1100 (c) 1300
  27. 27.Best estimate of 592 + 255? (a) 700 (b) 1100 (c) 900
  28. 28.Best estimate of 80 × 76? (a) 6400 (b) 64000 (c) 640
  29. 29.Best estimate of 77 × 30? (a) 24000 (b) 240 (c) 2400
  30. 30.Best estimate of 727 + 412? (a) 1300 (b) 900 (c) 1100
  31. 31.Best estimate of 74 × 17? (a) 14000 (b) 140 (c) 1400
  32. 32.Best estimate of 77 × 90? (a) 7200 (b) 72000 (c) 720
  33. 33.Best estimate of 71 × 81? (a) 5600 (b) 56000 (c) 560
  34. 34.Best estimate of 203 + 409? (a) 400 (b) 600 (c) 800
  35. 35.Best estimate of 18 × 84? (a) 16000 (b) 160 (c) 1600
  36. 36.Best estimate of 26 × 23? (a) 6000 (b) 600 (c) 60
  37. 37.Best estimate of 46 × 78? (a) 400 (b) 40000 (c) 4000
  38. 38.Best estimate of 540 + 271? (a) 600 (b) 800 (c) 1000
  39. 39.Best estimate of 433 + 382? (a) 800 (b) 1000 (c) 600
  40. 40.Best estimate of 241 + 473? (a) 700 (b) 900 (c) 500

Answer key

  1. 1000
  2. 4000
  3. 1600
  4. 1400
  5. 4200
  6. 3200
  7. 1000
  8. 3600
  9. 800
  10. 800
  11. 2700
  12. 900
  13. 200
  14. 700
  15. 1200
  16. 1200
  17. 400
  18. 600
  19. 1200
  20. 1300
  21. 4800
  22. 2700
  23. 1300
  24. 4500
  25. 600
  26. 1300
  27. 900
  28. 6400
  29. 2400
  30. 1100
  31. 1400
  32. 7200
  33. 5600
  34. 600
  35. 1600
  36. 600
  37. 4000
  38. 800
  39. 800
  40. 700

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