← Rounding off and best estimate lesson New set →

Rounding Off and Estimation Worksheet

Mental maths lesson 15: Rounding off and best estimate · Set 377 · 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 651 + 699? (a) 1600 (b) 1400 (c) 1200
  2. 2.Best estimate of 570 + 393? (a) 800 (b) 1000 (c) 1200
  3. 3.Best estimate of 19 × 38? (a) 80 (b) 800 (c) 8000
  4. 4.Best estimate of 428 + 149? (a) 700 (b) 300 (c) 500
  5. 5.Best estimate of 59 × 56? (a) 360 (b) 3600 (c) 36000
  6. 6.Best estimate of 227 + 462? (a) 900 (b) 500 (c) 700
  7. 7.Best estimate of 578 + 253? (a) 900 (b) 1100 (c) 700
  8. 8.Best estimate of 50 × 72? (a) 35000 (b) 350 (c) 3500
  9. 9.Best estimate of 679 + 735? (a) 1600 (b) 1400 (c) 1200
  10. 10.Best estimate of 94 × 20? (a) 1800 (b) 18000 (c) 180
  11. 11.Best estimate of 879 + 515? (a) 1400 (b) 1200 (c) 1600
  12. 12.Best estimate of 213 + 352? (a) 600 (b) 400 (c) 800
  13. 13.Best estimate of 64 × 19? (a) 1200 (b) 12000 (c) 120
  14. 14.Best estimate of 47 × 82? (a) 400 (b) 4000 (c) 40000
  15. 15.Best estimate of 27 × 59? (a) 18000 (b) 180 (c) 1800
  16. 16.Best estimate of 469 + 249? (a) 700 (b) 500 (c) 900
  17. 17.Best estimate of 57 × 19? (a) 120 (b) 1200 (c) 12000
  18. 18.Best estimate of 668 + 590? (a) 1300 (b) 1100 (c) 1500
  19. 19.Best estimate of 66 × 69? (a) 490 (b) 4900 (c) 49000
  20. 20.Best estimate of 141 + 806? (a) 700 (b) 900 (c) 1100
  21. 21.Best estimate of 82 × 72? (a) 560 (b) 56000 (c) 5600
  22. 22.Best estimate of 84 × 90? (a) 7200 (b) 72000 (c) 720
  23. 23.Best estimate of 44 × 16? (a) 8000 (b) 800 (c) 80
  24. 24.Best estimate of 48 × 67? (a) 35000 (b) 3500 (c) 350
  25. 25.Best estimate of 577 + 768? (a) 1400 (b) 1600 (c) 1200
  26. 26.Best estimate of 22 × 32? (a) 600 (b) 6000 (c) 60
  27. 27.Best estimate of 325 + 690? (a) 1000 (b) 800 (c) 1200
  28. 28.Best estimate of 40 × 34? (a) 12000 (b) 120 (c) 1200
  29. 29.Best estimate of 431 + 546? (a) 900 (b) 700 (c) 1100
  30. 30.Best estimate of 33 × 44? (a) 12000 (b) 1200 (c) 120
  31. 31.Best estimate of 36 × 63? (a) 24000 (b) 240 (c) 2400
  32. 32.Best estimate of 50 × 31? (a) 150 (b) 1500 (c) 15000
  33. 33.Best estimate of 143 + 234? (a) 500 (b) 100 (c) 300
  34. 34.Best estimate of 781 + 697? (a) 1700 (b) 1300 (c) 1500
  35. 35.Best estimate of 86 × 70? (a) 63000 (b) 630 (c) 6300
  36. 36.Best estimate of 753 + 655? (a) 1700 (b) 1300 (c) 1500
  37. 37.Best estimate of 86 × 63? (a) 5400 (b) 540 (c) 54000
  38. 38.Best estimate of 22 × 23? (a) 40 (b) 400 (c) 4000
  39. 39.Best estimate of 682 + 673? (a) 1400 (b) 1200 (c) 1600
  40. 40.Best estimate of 862 + 699? (a) 1600 (b) 1800 (c) 1400

Answer key

  1. 1400
  2. 1000
  3. 800
  4. 500
  5. 3600
  6. 700
  7. 900
  8. 3500
  9. 1400
  10. 1800
  11. 1400
  12. 600
  13. 1200
  14. 4000
  15. 1800
  16. 700
  17. 1200
  18. 1300
  19. 4900
  20. 900
  21. 5600
  22. 7200
  23. 800
  24. 3500
  25. 1400
  26. 600
  27. 1000
  28. 1200
  29. 900
  30. 1200
  31. 2400
  32. 1500
  33. 300
  34. 1500
  35. 6300
  36. 1500
  37. 5400
  38. 400
  39. 1400
  40. 1600

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