← Rounding off and best estimate lesson New set →

Rounding Off and Estimation Worksheet

Mental maths lesson 15: Rounding off and best estimate · Set 243 · 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 573 + 392? (a) 1200 (b) 800 (c) 1000
  2. 2.Best estimate of 587 + 127? (a) 900 (b) 500 (c) 700
  3. 3.Best estimate of 319 + 602? (a) 1100 (b) 900 (c) 700
  4. 4.Best estimate of 741 + 339? (a) 800 (b) 1000 (c) 1200
  5. 5.Best estimate of 143 + 561? (a) 700 (b) 900 (c) 500
  6. 6.Best estimate of 18 × 23? (a) 40 (b) 400 (c) 4000
  7. 7.Best estimate of 283 + 804? (a) 1300 (b) 1100 (c) 900
  8. 8.Best estimate of 717 + 359? (a) 1300 (b) 900 (c) 1100
  9. 9.Best estimate of 227 + 319? (a) 500 (b) 700 (c) 300
  10. 10.Best estimate of 84 × 12? (a) 80 (b) 800 (c) 8000
  11. 11.Best estimate of 76 × 27? (a) 24000 (b) 2400 (c) 240
  12. 12.Best estimate of 274 + 637? (a) 900 (b) 1100 (c) 700
  13. 13.Best estimate of 41 × 94? (a) 3600 (b) 360 (c) 36000
  14. 14.Best estimate of 628 + 285? (a) 900 (b) 700 (c) 1100
  15. 15.Best estimate of 207 + 269? (a) 700 (b) 500 (c) 300
  16. 16.Best estimate of 716 + 427? (a) 1300 (b) 1100 (c) 900
  17. 17.Best estimate of 83 × 39? (a) 32000 (b) 320 (c) 3200
  18. 18.Best estimate of 199 + 715? (a) 700 (b) 900 (c) 1100
  19. 19.Best estimate of 98 × 43? (a) 4000 (b) 40000 (c) 400
  20. 20.Best estimate of 370 + 456? (a) 900 (b) 700 (c) 1100
  21. 21.Best estimate of 213 + 748? (a) 700 (b) 1100 (c) 900
  22. 22.Best estimate of 425 + 494? (a) 1100 (b) 900 (c) 700
  23. 23.Best estimate of 70 × 48? (a) 3500 (b) 35000 (c) 350
  24. 24.Best estimate of 677 + 365? (a) 1100 (b) 900 (c) 1300
  25. 25.Best estimate of 628 + 804? (a) 1400 (b) 1600 (c) 1200
  26. 26.Best estimate of 42 × 31? (a) 1200 (b) 12000 (c) 120
  27. 27.Best estimate of 498 + 379? (a) 900 (b) 700 (c) 1100
  28. 28.Best estimate of 310 + 346? (a) 600 (b) 400 (c) 800
  29. 29.Best estimate of 183 + 868? (a) 1100 (b) 1300 (c) 900
  30. 30.Best estimate of 44 × 23? (a) 800 (b) 80 (c) 8000
  31. 31.Best estimate of 93 × 58? (a) 5400 (b) 54000 (c) 540
  32. 32.Best estimate of 19 × 24? (a) 4000 (b) 400 (c) 40
  33. 33.Best estimate of 134 + 220? (a) 300 (b) 500 (c) 100
  34. 34.Best estimate of 36 × 94? (a) 3600 (b) 36000 (c) 360
  35. 35.Best estimate of 830 + 588? (a) 1200 (b) 1400 (c) 1600
  36. 36.Best estimate of 351 + 408? (a) 1000 (b) 800 (c) 600
  37. 37.Best estimate of 84 × 98? (a) 80000 (b) 8000 (c) 800
  38. 38.Best estimate of 635 + 174? (a) 1000 (b) 600 (c) 800
  39. 39.Best estimate of 49 × 20? (a) 1000 (b) 10000 (c) 100
  40. 40.Best estimate of 759 + 313? (a) 1300 (b) 900 (c) 1100

Answer key

  1. 1000
  2. 700
  3. 900
  4. 1000
  5. 700
  6. 400
  7. 1100
  8. 1100
  9. 500
  10. 800
  11. 2400
  12. 900
  13. 3600
  14. 900
  15. 500
  16. 1100
  17. 3200
  18. 900
  19. 4000
  20. 900
  21. 900
  22. 900
  23. 3500
  24. 1100
  25. 1400
  26. 1200
  27. 900
  28. 600
  29. 1100
  30. 800
  31. 5400
  32. 400
  33. 300
  34. 3600
  35. 1400
  36. 800
  37. 8000
  38. 800
  39. 1000
  40. 1100

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