← Rounding off and best estimate lesson New set →

Rounding Off and Estimation Worksheet

Mental maths lesson 15: Rounding off and best estimate · Set 928 · 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 16 × 48? (a) 100 (b) 1000 (c) 10000
  2. 2.Best estimate of 145 + 546? (a) 600 (b) 400 (c) 800
  3. 3.Best estimate of 39 × 29? (a) 12000 (b) 120 (c) 1200
  4. 4.Best estimate of 18 × 36? (a) 8000 (b) 80 (c) 800
  5. 5.Best estimate of 66 × 77? (a) 5600 (b) 560 (c) 56000
  6. 6.Best estimate of 154 + 820? (a) 1200 (b) 1000 (c) 800
  7. 7.Best estimate of 388 + 600? (a) 1000 (b) 800 (c) 1200
  8. 8.Best estimate of 605 + 713? (a) 1500 (b) 1100 (c) 1300
  9. 9.Best estimate of 77 × 20? (a) 160 (b) 16000 (c) 1600
  10. 10.Best estimate of 462 + 738? (a) 1000 (b) 1200 (c) 1400
  11. 11.Best estimate of 495 + 259? (a) 600 (b) 800 (c) 1000
  12. 12.Best estimate of 637 + 860? (a) 1700 (b) 1500 (c) 1300
  13. 13.Best estimate of 48 × 18? (a) 1000 (b) 100 (c) 10000
  14. 14.Best estimate of 527 + 394? (a) 900 (b) 1100 (c) 700
  15. 15.Best estimate of 411 + 509? (a) 700 (b) 1100 (c) 900
  16. 16.Best estimate of 62 × 61? (a) 36000 (b) 360 (c) 3600
  17. 17.Best estimate of 27 × 89? (a) 27000 (b) 270 (c) 2700
  18. 18.Best estimate of 609 + 279? (a) 700 (b) 1100 (c) 900
  19. 19.Best estimate of 186 + 817? (a) 800 (b) 1200 (c) 1000
  20. 20.Best estimate of 83 × 13? (a) 8000 (b) 80 (c) 800
  21. 21.Best estimate of 817 + 295? (a) 1300 (b) 900 (c) 1100
  22. 22.Best estimate of 301 + 554? (a) 1100 (b) 700 (c) 900
  23. 23.Best estimate of 21 × 27? (a) 60 (b) 6000 (c) 600
  24. 24.Best estimate of 76 × 59? (a) 4800 (b) 480 (c) 48000
  25. 25.Best estimate of 246 + 561? (a) 800 (b) 600 (c) 1000
  26. 26.Best estimate of 557 + 678? (a) 1500 (b) 1100 (c) 1300
  27. 27.Best estimate of 852 + 628? (a) 1700 (b) 1500 (c) 1300
  28. 28.Best estimate of 875 + 570? (a) 1500 (b) 1700 (c) 1300
  29. 29.Best estimate of 21 × 34? (a) 6000 (b) 60 (c) 600
  30. 30.Best estimate of 97 × 18? (a) 2000 (b) 20000 (c) 200
  31. 31.Best estimate of 752 + 179? (a) 1200 (b) 1000 (c) 800
  32. 32.Best estimate of 33 × 86? (a) 2700 (b) 27000 (c) 270
  33. 33.Best estimate of 591 + 414? (a) 1200 (b) 1000 (c) 800
  34. 34.Best estimate of 310 + 782? (a) 900 (b) 1300 (c) 1100
  35. 35.Best estimate of 63 × 49? (a) 30000 (b) 3000 (c) 300
  36. 36.Best estimate of 854 + 356? (a) 1100 (b) 1300 (c) 1500
  37. 37.Best estimate of 322 + 807? (a) 900 (b) 1100 (c) 1300
  38. 38.Best estimate of 245 + 621? (a) 1000 (b) 800 (c) 600
  39. 39.Best estimate of 632 + 617? (a) 1200 (b) 1000 (c) 1400
  40. 40.Best estimate of 56 × 91? (a) 5400 (b) 54000 (c) 540

Answer key

  1. 1000
  2. 600
  3. 1200
  4. 800
  5. 5600
  6. 1000
  7. 1000
  8. 1300
  9. 1600
  10. 1200
  11. 800
  12. 1500
  13. 1000
  14. 900
  15. 900
  16. 3600
  17. 2700
  18. 900
  19. 1000
  20. 800
  21. 1100
  22. 900
  23. 600
  24. 4800
  25. 800
  26. 1300
  27. 1500
  28. 1500
  29. 600
  30. 2000
  31. 1000
  32. 2700
  33. 1000
  34. 1100
  35. 3000
  36. 1300
  37. 1100
  38. 800
  39. 1200
  40. 5400

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