← Rounding off and best estimate lesson New set →

Rounding Off and Estimation Worksheet

Mental maths lesson 15: Rounding off and best estimate · Set 967 · 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 187 + 802? (a) 1000 (b) 1200 (c) 800
  2. 2.Best estimate of 63 × 19? (a) 1200 (b) 120 (c) 12000
  3. 3.Best estimate of 343 + 700? (a) 800 (b) 1000 (c) 1200
  4. 4.Best estimate of 301 + 603? (a) 700 (b) 900 (c) 1100
  5. 5.Best estimate of 50 × 56? (a) 300 (b) 30000 (c) 3000
  6. 6.Best estimate of 23 × 67? (a) 1400 (b) 140 (c) 14000
  7. 7.Best estimate of 37 × 88? (a) 3600 (b) 36000 (c) 360
  8. 8.Best estimate of 68 × 46? (a) 350 (b) 3500 (c) 35000
  9. 9.Best estimate of 419 + 274? (a) 700 (b) 900 (c) 500
  10. 10.Best estimate of 57 × 68? (a) 42000 (b) 4200 (c) 420
  11. 11.Best estimate of 66 × 70? (a) 490 (b) 4900 (c) 49000
  12. 12.Best estimate of 43 × 41? (a) 160 (b) 1600 (c) 16000
  13. 13.Best estimate of 36 × 62? (a) 240 (b) 2400 (c) 24000
  14. 14.Best estimate of 79 × 16? (a) 160 (b) 16000 (c) 1600
  15. 15.Best estimate of 66 × 36? (a) 2800 (b) 28000 (c) 280
  16. 16.Best estimate of 712 + 312? (a) 800 (b) 1000 (c) 1200
  17. 17.Best estimate of 396 + 349? (a) 500 (b) 900 (c) 700
  18. 18.Best estimate of 83 × 56? (a) 48000 (b) 4800 (c) 480
  19. 19.Best estimate of 70 × 49? (a) 3500 (b) 350 (c) 35000
  20. 20.Best estimate of 34 × 52? (a) 150 (b) 15000 (c) 1500
  21. 21.Best estimate of 26 × 23? (a) 6000 (b) 600 (c) 60
  22. 22.Best estimate of 239 + 433? (a) 600 (b) 400 (c) 800
  23. 23.Best estimate of 398 + 317? (a) 500 (b) 700 (c) 900
  24. 24.Best estimate of 144 + 795? (a) 700 (b) 900 (c) 1100
  25. 25.Best estimate of 67 × 56? (a) 4200 (b) 420 (c) 42000
  26. 26.Best estimate of 213 + 293? (a) 300 (b) 700 (c) 500
  27. 27.Best estimate of 63 × 24? (a) 12000 (b) 1200 (c) 120
  28. 28.Best estimate of 19 × 17? (a) 400 (b) 4000 (c) 40
  29. 29.Best estimate of 435 + 423? (a) 1000 (b) 600 (c) 800
  30. 30.Best estimate of 30 × 12? (a) 300 (b) 30 (c) 3000
  31. 31.Best estimate of 519 + 545? (a) 800 (b) 1000 (c) 1200
  32. 32.Best estimate of 159 + 656? (a) 1100 (b) 700 (c) 900
  33. 33.Best estimate of 72 × 73? (a) 4900 (b) 490 (c) 49000
  34. 34.Best estimate of 46 × 89? (a) 45000 (b) 4500 (c) 450
  35. 35.Best estimate of 60 × 60? (a) 360 (b) 3600 (c) 36000
  36. 36.Best estimate of 393 + 223? (a) 400 (b) 800 (c) 600
  37. 37.Best estimate of 719 + 220? (a) 1100 (b) 900 (c) 700
  38. 38.Best estimate of 26 × 76? (a) 240 (b) 2400 (c) 24000
  39. 39.Best estimate of 97 × 70? (a) 70000 (b) 700 (c) 7000
  40. 40.Best estimate of 274 + 544? (a) 800 (b) 1000 (c) 600

Answer key

  1. 1000
  2. 1200
  3. 1000
  4. 900
  5. 3000
  6. 1400
  7. 3600
  8. 3500
  9. 700
  10. 4200
  11. 4900
  12. 1600
  13. 2400
  14. 1600
  15. 2800
  16. 1000
  17. 700
  18. 4800
  19. 3500
  20. 1500
  21. 600
  22. 600
  23. 700
  24. 900
  25. 4200
  26. 500
  27. 1200
  28. 400
  29. 800
  30. 300
  31. 1000
  32. 900
  33. 4900
  34. 4500
  35. 3600
  36. 600
  37. 900
  38. 2400
  39. 7000
  40. 800

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