← Rounding off and best estimate lesson New set →

Rounding Off and Estimation Worksheet

Mental maths lesson 15: Rounding off and best estimate · Set 672 · 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 236 + 167? (a) 200 (b) 600 (c) 400
  2. 2.Best estimate of 83 × 86? (a) 720 (b) 72000 (c) 7200
  3. 3.Best estimate of 94 × 86? (a) 8100 (b) 810 (c) 81000
  4. 4.Best estimate of 597 + 824? (a) 1400 (b) 1600 (c) 1200
  5. 5.Best estimate of 56 × 20? (a) 1200 (b) 12000 (c) 120
  6. 6.Best estimate of 39 × 23? (a) 800 (b) 8000 (c) 80
  7. 7.Best estimate of 37 × 32? (a) 120 (b) 12000 (c) 1200
  8. 8.Best estimate of 833 + 162? (a) 1200 (b) 1000 (c) 800
  9. 9.Best estimate of 49 × 63? (a) 3000 (b) 30000 (c) 300
  10. 10.Best estimate of 88 × 14? (a) 9000 (b) 900 (c) 90
  11. 11.Best estimate of 36 × 39? (a) 160 (b) 1600 (c) 16000
  12. 12.Best estimate of 276 + 327? (a) 600 (b) 400 (c) 800
  13. 13.Best estimate of 62 × 39? (a) 240 (b) 24000 (c) 2400
  14. 14.Best estimate of 371 + 504? (a) 900 (b) 700 (c) 1100
  15. 15.Best estimate of 43 × 51? (a) 2000 (b) 20000 (c) 200
  16. 16.Best estimate of 24 × 97? (a) 2000 (b) 20000 (c) 200
  17. 17.Best estimate of 14 × 38? (a) 400 (b) 4000 (c) 40
  18. 18.Best estimate of 618 + 592? (a) 1200 (b) 1400 (c) 1000
  19. 19.Best estimate of 621 + 242? (a) 800 (b) 600 (c) 1000
  20. 20.Best estimate of 30 × 16? (a) 600 (b) 60 (c) 6000
  21. 21.Best estimate of 356 + 579? (a) 1000 (b) 1200 (c) 800
  22. 22.Best estimate of 563 + 265? (a) 1100 (b) 900 (c) 700
  23. 23.Best estimate of 391 + 617? (a) 1000 (b) 800 (c) 1200
  24. 24.Best estimate of 76 × 41? (a) 320 (b) 3200 (c) 32000
  25. 25.Best estimate of 86 × 74? (a) 63000 (b) 6300 (c) 630
  26. 26.Best estimate of 748 + 212? (a) 1100 (b) 900 (c) 700
  27. 27.Best estimate of 81 × 57? (a) 4800 (b) 48000 (c) 480
  28. 28.Best estimate of 374 + 353? (a) 1000 (b) 600 (c) 800
  29. 29.Best estimate of 763 + 649? (a) 1600 (b) 1400 (c) 1200
  30. 30.Best estimate of 684 + 783? (a) 1700 (b) 1300 (c) 1500
  31. 31.Best estimate of 28 × 47? (a) 15000 (b) 150 (c) 1500
  32. 32.Best estimate of 575 + 137? (a) 700 (b) 900 (c) 500
  33. 33.Best estimate of 37 × 41? (a) 160 (b) 16000 (c) 1600
  34. 34.Best estimate of 36 × 42? (a) 160 (b) 16000 (c) 1600
  35. 35.Best estimate of 32 × 91? (a) 270 (b) 2700 (c) 27000
  36. 36.Best estimate of 12 × 83? (a) 8000 (b) 800 (c) 80
  37. 37.Best estimate of 530 + 829? (a) 1500 (b) 1300 (c) 1100
  38. 38.Best estimate of 420 + 699? (a) 900 (b) 1300 (c) 1100
  39. 39.Best estimate of 413 + 729? (a) 1100 (b) 900 (c) 1300
  40. 40.Best estimate of 44 × 54? (a) 200 (b) 20000 (c) 2000

Answer key

  1. 400
  2. 7200
  3. 8100
  4. 1400
  5. 1200
  6. 800
  7. 1200
  8. 1000
  9. 3000
  10. 900
  11. 1600
  12. 600
  13. 2400
  14. 900
  15. 2000
  16. 2000
  17. 400
  18. 1200
  19. 800
  20. 600
  21. 1000
  22. 900
  23. 1000
  24. 3200
  25. 6300
  26. 900
  27. 4800
  28. 800
  29. 1400
  30. 1500
  31. 1500
  32. 700
  33. 1600
  34. 1600
  35. 2700
  36. 800
  37. 1300
  38. 1100
  39. 1100
  40. 2000

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