← Rounding off and best estimate lesson New set →

Rounding Off and Estimation Worksheet

Mental maths lesson 15: Rounding off and best estimate · Set 370 · 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 559 + 487? (a) 900 (b) 1100 (c) 1300
  2. 2.Best estimate of 448 + 407? (a) 600 (b) 800 (c) 1000
  3. 3.Best estimate of 61 × 28? (a) 1800 (b) 180 (c) 18000
  4. 4.Best estimate of 59 × 23? (a) 1200 (b) 12000 (c) 120
  5. 5.Best estimate of 72 × 78? (a) 560 (b) 5600 (c) 56000
  6. 6.Best estimate of 706 + 522? (a) 1000 (b) 1400 (c) 1200
  7. 7.Best estimate of 78 × 64? (a) 480 (b) 4800 (c) 48000
  8. 8.Best estimate of 120 + 835? (a) 900 (b) 1100 (c) 700
  9. 9.Best estimate of 22 × 57? (a) 120 (b) 1200 (c) 12000
  10. 10.Best estimate of 50 × 96? (a) 50000 (b) 5000 (c) 500
  11. 11.Best estimate of 668 + 161? (a) 900 (b) 700 (c) 1100
  12. 12.Best estimate of 82 × 98? (a) 800 (b) 80000 (c) 8000
  13. 13.Best estimate of 68 × 26? (a) 2100 (b) 210 (c) 21000
  14. 14.Best estimate of 49 × 61? (a) 3000 (b) 300 (c) 30000
  15. 15.Best estimate of 87 × 77? (a) 720 (b) 72000 (c) 7200
  16. 16.Best estimate of 23 × 54? (a) 1000 (b) 100 (c) 10000
  17. 17.Best estimate of 537 + 144? (a) 800 (b) 400 (c) 600
  18. 18.Best estimate of 646 + 785? (a) 1200 (b) 1400 (c) 1600
  19. 19.Best estimate of 48 × 27? (a) 150 (b) 1500 (c) 15000
  20. 20.Best estimate of 31 × 53? (a) 1500 (b) 150 (c) 15000
  21. 21.Best estimate of 54 × 33? (a) 150 (b) 15000 (c) 1500
  22. 22.Best estimate of 74 × 24? (a) 1400 (b) 14000 (c) 140
  23. 23.Best estimate of 489 + 379? (a) 1100 (b) 900 (c) 700
  24. 24.Best estimate of 470 + 719? (a) 1400 (b) 1000 (c) 1200
  25. 25.Best estimate of 32 × 62? (a) 18000 (b) 1800 (c) 180
  26. 26.Best estimate of 819 + 315? (a) 900 (b) 1300 (c) 1100
  27. 27.Best estimate of 661 + 283? (a) 800 (b) 1000 (c) 1200
  28. 28.Best estimate of 53 × 28? (a) 15000 (b) 150 (c) 1500
  29. 29.Best estimate of 135 + 493? (a) 600 (b) 800 (c) 400
  30. 30.Best estimate of 223 + 833? (a) 800 (b) 1200 (c) 1000
  31. 31.Best estimate of 27 × 76? (a) 240 (b) 2400 (c) 24000
  32. 32.Best estimate of 297 + 177? (a) 500 (b) 700 (c) 300
  33. 33.Best estimate of 684 + 863? (a) 1800 (b) 1400 (c) 1600
  34. 34.Best estimate of 158 + 122? (a) 300 (b) 500 (c) 100
  35. 35.Best estimate of 849 + 795? (a) 1800 (b) 1600 (c) 1400
  36. 36.Best estimate of 26 × 36? (a) 12000 (b) 120 (c) 1200
  37. 37.Best estimate of 495 + 573? (a) 1300 (b) 1100 (c) 900
  38. 38.Best estimate of 242 + 221? (a) 400 (b) 200 (c) 600
  39. 39.Best estimate of 168 + 712? (a) 900 (b) 1100 (c) 700
  40. 40.Best estimate of 17 × 60? (a) 1200 (b) 12000 (c) 120

Answer key

  1. 1100
  2. 800
  3. 1800
  4. 1200
  5. 5600
  6. 1200
  7. 4800
  8. 900
  9. 1200
  10. 5000
  11. 900
  12. 8000
  13. 2100
  14. 3000
  15. 7200
  16. 1000
  17. 600
  18. 1400
  19. 1500
  20. 1500
  21. 1500
  22. 1400
  23. 900
  24. 1200
  25. 1800
  26. 1100
  27. 1000
  28. 1500
  29. 600
  30. 1000
  31. 2400
  32. 500
  33. 1600
  34. 300
  35. 1600
  36. 1200
  37. 1100
  38. 400
  39. 900
  40. 1200

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