← Rounding off and best estimate lesson New set →

Rounding Off and Estimation Worksheet

Mental maths lesson 15: Rounding off and best estimate · Set 743 · 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 91 × 49? (a) 45000 (b) 450 (c) 4500
  2. 2.Best estimate of 58 × 16? (a) 1200 (b) 120 (c) 12000
  3. 3.Best estimate of 83 × 88? (a) 7200 (b) 72000 (c) 720
  4. 4.Best estimate of 44 × 90? (a) 3600 (b) 360 (c) 36000
  5. 5.Best estimate of 626 + 135? (a) 900 (b) 500 (c) 700
  6. 6.Best estimate of 133 + 600? (a) 900 (b) 700 (c) 500
  7. 7.Best estimate of 90 × 14? (a) 900 (b) 9000 (c) 90
  8. 8.Best estimate of 151 + 491? (a) 700 (b) 500 (c) 900
  9. 9.Best estimate of 768 + 348? (a) 1100 (b) 900 (c) 1300
  10. 10.Best estimate of 271 + 555? (a) 900 (b) 1100 (c) 700
  11. 11.Best estimate of 384 + 583? (a) 1000 (b) 800 (c) 1200
  12. 12.Best estimate of 39 × 50? (a) 200 (b) 2000 (c) 20000
  13. 13.Best estimate of 87 × 16? (a) 180 (b) 18000 (c) 1800
  14. 14.Best estimate of 77 × 17? (a) 1600 (b) 16000 (c) 160
  15. 15.Best estimate of 53 × 53? (a) 250 (b) 25000 (c) 2500
  16. 16.Best estimate of 146 + 487? (a) 600 (b) 800 (c) 400
  17. 17.Best estimate of 16 × 41? (a) 80 (b) 8000 (c) 800
  18. 18.Best estimate of 861 + 287? (a) 1400 (b) 1200 (c) 1000
  19. 19.Best estimate of 296 + 636? (a) 900 (b) 1100 (c) 700
  20. 20.Best estimate of 77 × 34? (a) 24000 (b) 2400 (c) 240
  21. 21.Best estimate of 74 × 98? (a) 70000 (b) 700 (c) 7000
  22. 22.Best estimate of 96 × 92? (a) 900 (b) 9000 (c) 90000
  23. 23.Best estimate of 54 × 88? (a) 4500 (b) 450 (c) 45000
  24. 24.Best estimate of 162 + 343? (a) 500 (b) 300 (c) 700
  25. 25.Best estimate of 89 × 74? (a) 630 (b) 6300 (c) 63000
  26. 26.Best estimate of 29 × 42? (a) 1200 (b) 12000 (c) 120
  27. 27.Best estimate of 77 × 98? (a) 8000 (b) 800 (c) 80000
  28. 28.Best estimate of 93 × 86? (a) 8100 (b) 81000 (c) 810
  29. 29.Best estimate of 86 × 18? (a) 18000 (b) 1800 (c) 180
  30. 30.Best estimate of 564 + 200? (a) 800 (b) 600 (c) 1000
  31. 31.Best estimate of 14 × 12? (a) 1000 (b) 100 (c) 10
  32. 32.Best estimate of 28 × 98? (a) 30000 (b) 300 (c) 3000
  33. 33.Best estimate of 601 + 202? (a) 1000 (b) 800 (c) 600
  34. 34.Best estimate of 536 + 184? (a) 700 (b) 500 (c) 900
  35. 35.Best estimate of 23 × 51? (a) 10000 (b) 100 (c) 1000
  36. 36.Best estimate of 835 + 383? (a) 1400 (b) 1000 (c) 1200
  37. 37.Best estimate of 291 + 165? (a) 700 (b) 500 (c) 300
  38. 38.Best estimate of 351 + 129? (a) 300 (b) 700 (c) 500
  39. 39.Best estimate of 404 + 299? (a) 900 (b) 500 (c) 700
  40. 40.Best estimate of 93 × 74? (a) 6300 (b) 63000 (c) 630

Answer key

  1. 4500
  2. 1200
  3. 7200
  4. 3600
  5. 700
  6. 700
  7. 900
  8. 700
  9. 1100
  10. 900
  11. 1000
  12. 2000
  13. 1800
  14. 1600
  15. 2500
  16. 600
  17. 800
  18. 1200
  19. 900
  20. 2400
  21. 7000
  22. 9000
  23. 4500
  24. 500
  25. 6300
  26. 1200
  27. 8000
  28. 8100
  29. 1800
  30. 800
  31. 100
  32. 3000
  33. 800
  34. 700
  35. 1000
  36. 1200
  37. 500
  38. 500
  39. 700
  40. 6300

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