← Rounding off and best estimate lesson New set →

Rounding Off and Estimation Worksheet

Mental maths lesson 15: Rounding off and best estimate · Set 321 · 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 677 + 151? (a) 900 (b) 1100 (c) 700
  2. 2.Best estimate of 87 × 30? (a) 2700 (b) 27000 (c) 270
  3. 3.Best estimate of 784 + 522? (a) 1500 (b) 1300 (c) 1100
  4. 4.Best estimate of 266 + 193? (a) 500 (b) 300 (c) 700
  5. 5.Best estimate of 535 + 842? (a) 1300 (b) 1500 (c) 1100
  6. 6.Best estimate of 68 × 34? (a) 21000 (b) 210 (c) 2100
  7. 7.Best estimate of 49 × 23? (a) 1000 (b) 10000 (c) 100
  8. 8.Best estimate of 396 + 487? (a) 700 (b) 900 (c) 1100
  9. 9.Best estimate of 162 + 749? (a) 1100 (b) 900 (c) 700
  10. 10.Best estimate of 373 + 141? (a) 500 (b) 700 (c) 300
  11. 11.Best estimate of 63 × 27? (a) 1800 (b) 180 (c) 18000
  12. 12.Best estimate of 255 + 757? (a) 1100 (b) 900 (c) 1300
  13. 13.Best estimate of 43 × 48? (a) 20000 (b) 2000 (c) 200
  14. 14.Best estimate of 39 × 76? (a) 3200 (b) 320 (c) 32000
  15. 15.Best estimate of 37 × 90? (a) 36000 (b) 3600 (c) 360
  16. 16.Best estimate of 647 + 293? (a) 1100 (b) 900 (c) 700
  17. 17.Best estimate of 251 + 595? (a) 700 (b) 1100 (c) 900
  18. 18.Best estimate of 607 + 513? (a) 1300 (b) 900 (c) 1100
  19. 19.Best estimate of 645 + 207? (a) 800 (b) 1000 (c) 600
  20. 20.Best estimate of 97 × 77? (a) 8000 (b) 80000 (c) 800
  21. 21.Best estimate of 93 × 16? (a) 180 (b) 18000 (c) 1800
  22. 22.Best estimate of 90 × 68? (a) 6300 (b) 63000 (c) 630
  23. 23.Best estimate of 194 + 763? (a) 800 (b) 1200 (c) 1000
  24. 24.Best estimate of 21 × 58? (a) 12000 (b) 120 (c) 1200
  25. 25.Best estimate of 788 + 397? (a) 1400 (b) 1000 (c) 1200
  26. 26.Best estimate of 496 + 188? (a) 500 (b) 900 (c) 700
  27. 27.Best estimate of 470 + 153? (a) 900 (b) 500 (c) 700
  28. 28.Best estimate of 595 + 304? (a) 1100 (b) 900 (c) 700
  29. 29.Best estimate of 32 × 50? (a) 15000 (b) 1500 (c) 150
  30. 30.Best estimate of 571 + 136? (a) 700 (b) 900 (c) 500
  31. 31.Best estimate of 56 × 32? (a) 1800 (b) 180 (c) 18000
  32. 32.Best estimate of 216 + 598? (a) 600 (b) 800 (c) 1000
  33. 33.Best estimate of 66 × 23? (a) 14000 (b) 1400 (c) 140
  34. 34.Best estimate of 63 × 42? (a) 240 (b) 2400 (c) 24000
  35. 35.Best estimate of 410 + 682? (a) 1100 (b) 1300 (c) 900
  36. 36.Best estimate of 64 × 42? (a) 24000 (b) 240 (c) 2400
  37. 37.Best estimate of 94 × 62? (a) 540 (b) 5400 (c) 54000
  38. 38.Best estimate of 20 × 33? (a) 60 (b) 6000 (c) 600
  39. 39.Best estimate of 808 + 499? (a) 1100 (b) 1500 (c) 1300
  40. 40.Best estimate of 72 × 28? (a) 2100 (b) 21000 (c) 210

Answer key

  1. 900
  2. 2700
  3. 1300
  4. 500
  5. 1300
  6. 2100
  7. 1000
  8. 900
  9. 900
  10. 500
  11. 1800
  12. 1100
  13. 2000
  14. 3200
  15. 3600
  16. 900
  17. 900
  18. 1100
  19. 800
  20. 8000
  21. 1800
  22. 6300
  23. 1000
  24. 1200
  25. 1200
  26. 700
  27. 700
  28. 900
  29. 1500
  30. 700
  31. 1800
  32. 800
  33. 1400
  34. 2400
  35. 1100
  36. 2400
  37. 5400
  38. 600
  39. 1300
  40. 2100

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