← Rounding off and best estimate lesson New set →

Rounding Off and Estimation Worksheet

Mental maths lesson 15: Rounding off and best estimate · Set 707 · 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 179 + 366? (a) 600 (b) 800 (c) 400
  2. 2.Best estimate of 26 × 26? (a) 900 (b) 9000 (c) 90
  3. 3.Best estimate of 17 × 68? (a) 140 (b) 1400 (c) 14000
  4. 4.Best estimate of 69 × 44? (a) 2800 (b) 280 (c) 28000
  5. 5.Best estimate of 523 + 302? (a) 1000 (b) 600 (c) 800
  6. 6.Best estimate of 18 × 36? (a) 800 (b) 80 (c) 8000
  7. 7.Best estimate of 62 × 57? (a) 360 (b) 3600 (c) 36000
  8. 8.Best estimate of 613 + 661? (a) 1500 (b) 1300 (c) 1100
  9. 9.Best estimate of 234 + 840? (a) 1200 (b) 1000 (c) 800
  10. 10.Best estimate of 845 + 332? (a) 900 (b) 1300 (c) 1100
  11. 11.Best estimate of 298 + 547? (a) 600 (b) 1000 (c) 800
  12. 12.Best estimate of 18 × 12? (a) 2000 (b) 200 (c) 20
  13. 13.Best estimate of 664 + 148? (a) 600 (b) 1000 (c) 800
  14. 14.Best estimate of 247 + 251? (a) 700 (b) 500 (c) 300
  15. 15.Best estimate of 660 + 578? (a) 1500 (b) 1100 (c) 1300
  16. 16.Best estimate of 830 + 676? (a) 1300 (b) 1700 (c) 1500
  17. 17.Best estimate of 96 × 71? (a) 7000 (b) 700 (c) 70000
  18. 18.Best estimate of 32 × 94? (a) 2700 (b) 270 (c) 27000
  19. 19.Best estimate of 18 × 18? (a) 4000 (b) 400 (c) 40
  20. 20.Best estimate of 27 × 98? (a) 3000 (b) 300 (c) 30000
  21. 21.Best estimate of 80 × 82? (a) 6400 (b) 64000 (c) 640
  22. 22.Best estimate of 358 + 364? (a) 600 (b) 800 (c) 1000
  23. 23.Best estimate of 66 × 18? (a) 1400 (b) 140 (c) 14000
  24. 24.Best estimate of 743 + 205? (a) 700 (b) 1100 (c) 900
  25. 25.Best estimate of 847 + 722? (a) 1500 (b) 1300 (c) 1700
  26. 26.Best estimate of 19 × 23? (a) 4000 (b) 40 (c) 400
  27. 27.Best estimate of 648 + 596? (a) 1400 (b) 1000 (c) 1200
  28. 28.Best estimate of 471 + 151? (a) 700 (b) 900 (c) 500
  29. 29.Best estimate of 59 × 40? (a) 24000 (b) 240 (c) 2400
  30. 30.Best estimate of 24 × 32? (a) 600 (b) 60 (c) 6000
  31. 31.Best estimate of 17 × 26? (a) 6000 (b) 600 (c) 60
  32. 32.Best estimate of 165 + 851? (a) 900 (b) 1300 (c) 1100
  33. 33.Best estimate of 807 + 262? (a) 1300 (b) 900 (c) 1100
  34. 34.Best estimate of 827 + 602? (a) 1600 (b) 1200 (c) 1400
  35. 35.Best estimate of 88 × 58? (a) 5400 (b) 540 (c) 54000
  36. 36.Best estimate of 739 + 786? (a) 1500 (b) 1300 (c) 1700
  37. 37.Best estimate of 59 × 56? (a) 3600 (b) 36000 (c) 360
  38. 38.Best estimate of 415 + 563? (a) 1000 (b) 1200 (c) 800
  39. 39.Best estimate of 421 + 514? (a) 700 (b) 900 (c) 1100
  40. 40.Best estimate of 408 + 433? (a) 800 (b) 1000 (c) 600

Answer key

  1. 600
  2. 900
  3. 1400
  4. 2800
  5. 800
  6. 800
  7. 3600
  8. 1300
  9. 1000
  10. 1100
  11. 800
  12. 200
  13. 800
  14. 500
  15. 1300
  16. 1500
  17. 7000
  18. 2700
  19. 400
  20. 3000
  21. 6400
  22. 800
  23. 1400
  24. 900
  25. 1500
  26. 400
  27. 1200
  28. 700
  29. 2400
  30. 600
  31. 600
  32. 1100
  33. 1100
  34. 1400
  35. 5400
  36. 1500
  37. 3600
  38. 1000
  39. 900
  40. 800

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