← Rounding off and best estimate lesson New set →

Rounding Off and Estimation Worksheet

Mental maths lesson 15: Rounding off and best estimate · Set 840 · 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 761 + 589? (a) 1400 (b) 1200 (c) 1600
  2. 2.Best estimate of 785 + 228? (a) 800 (b) 1200 (c) 1000
  3. 3.Best estimate of 399 + 762? (a) 1400 (b) 1000 (c) 1200
  4. 4.Best estimate of 333 + 451? (a) 1000 (b) 800 (c) 600
  5. 5.Best estimate of 97 × 87? (a) 90000 (b) 9000 (c) 900
  6. 6.Best estimate of 26 × 34? (a) 9000 (b) 90 (c) 900
  7. 7.Best estimate of 228 + 209? (a) 200 (b) 600 (c) 400
  8. 8.Best estimate of 37 × 44? (a) 16000 (b) 160 (c) 1600
  9. 9.Best estimate of 242 + 482? (a) 900 (b) 700 (c) 500
  10. 10.Best estimate of 58 × 53? (a) 30000 (b) 300 (c) 3000
  11. 11.Best estimate of 73 × 81? (a) 5600 (b) 56000 (c) 560
  12. 12.Best estimate of 60 × 76? (a) 4800 (b) 48000 (c) 480
  13. 13.Best estimate of 97 × 56? (a) 60000 (b) 6000 (c) 600
  14. 14.Best estimate of 725 + 189? (a) 700 (b) 1100 (c) 900
  15. 15.Best estimate of 711 + 391? (a) 1100 (b) 1300 (c) 900
  16. 16.Best estimate of 403 + 257? (a) 700 (b) 900 (c) 500
  17. 17.Best estimate of 598 + 142? (a) 900 (b) 700 (c) 500
  18. 18.Best estimate of 44 × 42? (a) 160 (b) 1600 (c) 16000
  19. 19.Best estimate of 60 × 59? (a) 36000 (b) 360 (c) 3600
  20. 20.Best estimate of 325 + 791? (a) 1300 (b) 900 (c) 1100
  21. 21.Best estimate of 769 + 753? (a) 1600 (b) 1400 (c) 1800
  22. 22.Best estimate of 18 × 91? (a) 18000 (b) 180 (c) 1800
  23. 23.Best estimate of 168 + 730? (a) 1100 (b) 700 (c) 900
  24. 24.Best estimate of 34 × 20? (a) 60 (b) 6000 (c) 600
  25. 25.Best estimate of 406 + 618? (a) 800 (b) 1200 (c) 1000
  26. 26.Best estimate of 562 + 760? (a) 1400 (b) 1600 (c) 1200
  27. 27.Best estimate of 32 × 38? (a) 120 (b) 12000 (c) 1200
  28. 28.Best estimate of 69 × 82? (a) 5600 (b) 560 (c) 56000
  29. 29.Best estimate of 712 + 186? (a) 900 (b) 1100 (c) 700
  30. 30.Best estimate of 21 × 13? (a) 2000 (b) 200 (c) 20
  31. 31.Best estimate of 49 × 46? (a) 250 (b) 2500 (c) 25000
  32. 32.Best estimate of 823 + 811? (a) 1800 (b) 1600 (c) 1400
  33. 33.Best estimate of 538 + 179? (a) 700 (b) 900 (c) 500
  34. 34.Best estimate of 42 × 74? (a) 2800 (b) 280 (c) 28000
  35. 35.Best estimate of 29 × 89? (a) 27000 (b) 270 (c) 2700
  36. 36.Best estimate of 53 × 34? (a) 15000 (b) 1500 (c) 150
  37. 37.Best estimate of 553 + 351? (a) 1000 (b) 800 (c) 1200
  38. 38.Best estimate of 56 × 39? (a) 24000 (b) 240 (c) 2400
  39. 39.Best estimate of 29 × 69? (a) 21000 (b) 2100 (c) 210
  40. 40.Best estimate of 21 × 87? (a) 18000 (b) 180 (c) 1800

Answer key

  1. 1400
  2. 1000
  3. 1200
  4. 800
  5. 9000
  6. 900
  7. 400
  8. 1600
  9. 700
  10. 3000
  11. 5600
  12. 4800
  13. 6000
  14. 900
  15. 1100
  16. 700
  17. 700
  18. 1600
  19. 3600
  20. 1100
  21. 1600
  22. 1800
  23. 900
  24. 600
  25. 1000
  26. 1400
  27. 1200
  28. 5600
  29. 900
  30. 200
  31. 2500
  32. 1600
  33. 700
  34. 2800
  35. 2700
  36. 1500
  37. 1000
  38. 2400
  39. 2100
  40. 1800

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