← Rounding off and best estimate lesson New set →

Rounding Off and Estimation Worksheet

Mental maths lesson 15: Rounding off and best estimate · Set 3 · 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 81 × 86? (a) 720 (b) 72000 (c) 7200
  2. 2.Best estimate of 572 + 752? (a) 1200 (b) 1600 (c) 1400
  3. 3.Best estimate of 71 × 28? (a) 2100 (b) 210 (c) 21000
  4. 4.Best estimate of 618 + 481? (a) 1300 (b) 900 (c) 1100
  5. 5.Best estimate of 59 × 20? (a) 1200 (b) 12000 (c) 120
  6. 6.Best estimate of 483 + 178? (a) 500 (b) 700 (c) 900
  7. 7.Best estimate of 300 + 238? (a) 300 (b) 700 (c) 500
  8. 8.Best estimate of 26 × 77? (a) 2400 (b) 240 (c) 24000
  9. 9.Best estimate of 87 × 23? (a) 1800 (b) 180 (c) 18000
  10. 10.Best estimate of 27 × 50? (a) 15000 (b) 150 (c) 1500
  11. 11.Best estimate of 16 × 63? (a) 120 (b) 1200 (c) 12000
  12. 12.Best estimate of 38 × 74? (a) 280 (b) 2800 (c) 28000
  13. 13.Best estimate of 239 + 838? (a) 1200 (b) 1000 (c) 800
  14. 14.Best estimate of 641 + 412? (a) 800 (b) 1200 (c) 1000
  15. 15.Best estimate of 59 × 76? (a) 48000 (b) 480 (c) 4800
  16. 16.Best estimate of 41 × 33? (a) 12000 (b) 1200 (c) 120
  17. 17.Best estimate of 26 × 12? (a) 3000 (b) 30 (c) 300
  18. 18.Best estimate of 42 × 79? (a) 32000 (b) 320 (c) 3200
  19. 19.Best estimate of 29 × 96? (a) 3000 (b) 30000 (c) 300
  20. 20.Best estimate of 76 × 78? (a) 640 (b) 6400 (c) 64000
  21. 21.Best estimate of 695 + 616? (a) 1300 (b) 1500 (c) 1100
  22. 22.Best estimate of 91 × 48? (a) 4500 (b) 450 (c) 45000
  23. 23.Best estimate of 390 + 281? (a) 700 (b) 500 (c) 900
  24. 24.Best estimate of 531 + 439? (a) 1100 (b) 700 (c) 900
  25. 25.Best estimate of 18 × 16? (a) 40 (b) 400 (c) 4000
  26. 26.Best estimate of 671 + 314? (a) 1200 (b) 800 (c) 1000
  27. 27.Best estimate of 89 × 87? (a) 81000 (b) 810 (c) 8100
  28. 28.Best estimate of 400 + 353? (a) 600 (b) 1000 (c) 800
  29. 29.Best estimate of 13 × 83? (a) 80 (b) 8000 (c) 800
  30. 30.Best estimate of 98 × 89? (a) 900 (b) 90000 (c) 9000
  31. 31.Best estimate of 401 + 138? (a) 300 (b) 700 (c) 500
  32. 32.Best estimate of 790 + 443? (a) 1400 (b) 1000 (c) 1200
  33. 33.Best estimate of 12 × 60? (a) 600 (b) 60 (c) 6000
  34. 34.Best estimate of 58 × 87? (a) 5400 (b) 540 (c) 54000
  35. 35.Best estimate of 81 × 27? (a) 24000 (b) 2400 (c) 240
  36. 36.Best estimate of 212 + 326? (a) 300 (b) 700 (c) 500
  37. 37.Best estimate of 736 + 524? (a) 1400 (b) 1000 (c) 1200
  38. 38.Best estimate of 33 × 13? (a) 300 (b) 3000 (c) 30
  39. 39.Best estimate of 658 + 789? (a) 1300 (b) 1700 (c) 1500
  40. 40.Best estimate of 69 × 13? (a) 700 (b) 7000 (c) 70

Answer key

  1. 7200
  2. 1400
  3. 2100
  4. 1100
  5. 1200
  6. 700
  7. 500
  8. 2400
  9. 1800
  10. 1500
  11. 1200
  12. 2800
  13. 1000
  14. 1000
  15. 4800
  16. 1200
  17. 300
  18. 3200
  19. 3000
  20. 6400
  21. 1300
  22. 4500
  23. 700
  24. 900
  25. 400
  26. 1000
  27. 8100
  28. 800
  29. 800
  30. 9000
  31. 500
  32. 1200
  33. 600
  34. 5400
  35. 2400
  36. 500
  37. 1200
  38. 300
  39. 1500
  40. 700

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