← Rounding off and best estimate lesson New set →

Rounding Off and Estimation Worksheet

Mental maths lesson 15: Rounding off and best estimate · Set 24 · 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 394 + 476? (a) 900 (b) 1100 (c) 700
  2. 2.Best estimate of 662 + 332? (a) 1000 (b) 800 (c) 1200
  3. 3.Best estimate of 27 × 56? (a) 18000 (b) 1800 (c) 180
  4. 4.Best estimate of 170 + 357? (a) 800 (b) 600 (c) 400
  5. 5.Best estimate of 422 + 545? (a) 900 (b) 1100 (c) 700
  6. 6.Best estimate of 12 × 20? (a) 2000 (b) 20 (c) 200
  7. 7.Best estimate of 84 × 27? (a) 2400 (b) 24000 (c) 240
  8. 8.Best estimate of 32 × 38? (a) 120 (b) 1200 (c) 12000
  9. 9.Best estimate of 219 + 446? (a) 800 (b) 400 (c) 600
  10. 10.Best estimate of 30 × 83? (a) 240 (b) 2400 (c) 24000
  11. 11.Best estimate of 66 × 46? (a) 3500 (b) 35000 (c) 350
  12. 12.Best estimate of 70 × 66? (a) 49000 (b) 4900 (c) 490
  13. 13.Best estimate of 284 + 786? (a) 1100 (b) 1300 (c) 900
  14. 14.Best estimate of 23 × 49? (a) 100 (b) 10000 (c) 1000
  15. 15.Best estimate of 47 × 42? (a) 20000 (b) 200 (c) 2000
  16. 16.Best estimate of 74 × 46? (a) 35000 (b) 350 (c) 3500
  17. 17.Best estimate of 241 + 559? (a) 600 (b) 1000 (c) 800
  18. 18.Best estimate of 74 × 70? (a) 4900 (b) 49000 (c) 490
  19. 19.Best estimate of 159 + 527? (a) 700 (b) 900 (c) 500
  20. 20.Best estimate of 26 × 70? (a) 210 (b) 21000 (c) 2100
  21. 21.Best estimate of 562 + 259? (a) 1100 (b) 900 (c) 700
  22. 22.Best estimate of 688 + 569? (a) 1300 (b) 1100 (c) 1500
  23. 23.Best estimate of 167 + 268? (a) 300 (b) 500 (c) 700
  24. 24.Best estimate of 741 + 232? (a) 700 (b) 1100 (c) 900
  25. 25.Best estimate of 54 × 89? (a) 45000 (b) 4500 (c) 450
  26. 26.Best estimate of 819 + 192? (a) 1200 (b) 800 (c) 1000
  27. 27.Best estimate of 502 + 451? (a) 800 (b) 1000 (c) 1200
  28. 28.Best estimate of 21 × 39? (a) 8000 (b) 800 (c) 80
  29. 29.Best estimate of 31 × 64? (a) 180 (b) 18000 (c) 1800
  30. 30.Best estimate of 383 + 551? (a) 1200 (b) 800 (c) 1000
  31. 31.Best estimate of 36 × 22? (a) 80 (b) 8000 (c) 800
  32. 32.Best estimate of 27 × 12? (a) 3000 (b) 300 (c) 30
  33. 33.Best estimate of 782 + 178? (a) 800 (b) 1000 (c) 1200
  34. 34.Best estimate of 213 + 286? (a) 700 (b) 300 (c) 500
  35. 35.Best estimate of 57 × 33? (a) 1800 (b) 180 (c) 18000
  36. 36.Best estimate of 24 × 26? (a) 600 (b) 6000 (c) 60
  37. 37.Best estimate of 851 + 152? (a) 1300 (b) 900 (c) 1100
  38. 38.Best estimate of 800 + 660? (a) 1300 (b) 1500 (c) 1700
  39. 39.Best estimate of 305 + 583? (a) 700 (b) 900 (c) 1100
  40. 40.Best estimate of 14 × 44? (a) 4000 (b) 400 (c) 40

Answer key

  1. 900
  2. 1000
  3. 1800
  4. 600
  5. 900
  6. 200
  7. 2400
  8. 1200
  9. 600
  10. 2400
  11. 3500
  12. 4900
  13. 1100
  14. 1000
  15. 2000
  16. 3500
  17. 800
  18. 4900
  19. 700
  20. 2100
  21. 900
  22. 1300
  23. 500
  24. 900
  25. 4500
  26. 1000
  27. 1000
  28. 800
  29. 1800
  30. 1000
  31. 800
  32. 300
  33. 1000
  34. 500
  35. 1800
  36. 600
  37. 1100
  38. 1500
  39. 900
  40. 400

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