← Rounding off and best estimate lesson New set →

Rounding Off and Estimation Worksheet

Mental maths lesson 15: Rounding off and best estimate · Set 615 · 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 260 + 530? (a) 600 (b) 1000 (c) 800
  2. 2.Best estimate of 343 + 581? (a) 1100 (b) 700 (c) 900
  3. 3.Best estimate of 41 × 46? (a) 20000 (b) 2000 (c) 200
  4. 4.Best estimate of 66 × 78? (a) 56000 (b) 560 (c) 5600
  5. 5.Best estimate of 37 × 97? (a) 4000 (b) 400 (c) 40000
  6. 6.Best estimate of 456 + 233? (a) 500 (b) 900 (c) 700
  7. 7.Best estimate of 618 + 473? (a) 1100 (b) 1300 (c) 900
  8. 8.Best estimate of 56 × 57? (a) 3600 (b) 36000 (c) 360
  9. 9.Best estimate of 24 × 40? (a) 8000 (b) 800 (c) 80
  10. 10.Best estimate of 519 + 223? (a) 500 (b) 900 (c) 700
  11. 11.Best estimate of 358 + 478? (a) 1100 (b) 900 (c) 700
  12. 12.Best estimate of 56 × 81? (a) 48000 (b) 480 (c) 4800
  13. 13.Best estimate of 77 × 33? (a) 2400 (b) 240 (c) 24000
  14. 14.Best estimate of 56 × 46? (a) 3000 (b) 30000 (c) 300
  15. 15.Best estimate of 718 + 277? (a) 1200 (b) 800 (c) 1000
  16. 16.Best estimate of 86 × 89? (a) 81000 (b) 810 (c) 8100
  17. 17.Best estimate of 161 + 593? (a) 600 (b) 1000 (c) 800
  18. 18.Best estimate of 43 × 14? (a) 40 (b) 4000 (c) 400
  19. 19.Best estimate of 208 + 336? (a) 300 (b) 700 (c) 500
  20. 20.Best estimate of 94 × 88? (a) 810 (b) 8100 (c) 81000
  21. 21.Best estimate of 43 × 56? (a) 2400 (b) 24000 (c) 240
  22. 22.Best estimate of 545 + 515? (a) 1200 (b) 800 (c) 1000
  23. 23.Best estimate of 395 + 422? (a) 800 (b) 1000 (c) 600
  24. 24.Best estimate of 83 × 64? (a) 4800 (b) 480 (c) 48000
  25. 25.Best estimate of 772 + 590? (a) 1600 (b) 1200 (c) 1400
  26. 26.Best estimate of 131 + 477? (a) 400 (b) 600 (c) 800
  27. 27.Best estimate of 81 × 28? (a) 2400 (b) 24000 (c) 240
  28. 28.Best estimate of 67 × 79? (a) 560 (b) 56000 (c) 5600
  29. 29.Best estimate of 533 + 772? (a) 1300 (b) 1100 (c) 1500
  30. 30.Best estimate of 69 × 19? (a) 1400 (b) 140 (c) 14000
  31. 31.Best estimate of 67 × 32? (a) 2100 (b) 21000 (c) 210
  32. 32.Best estimate of 54 × 16? (a) 1000 (b) 10000 (c) 100
  33. 33.Best estimate of 56 × 24? (a) 12000 (b) 1200 (c) 120
  34. 34.Best estimate of 92 × 19? (a) 18000 (b) 180 (c) 1800
  35. 35.Best estimate of 192 + 173? (a) 600 (b) 400 (c) 200
  36. 36.Best estimate of 86 × 17? (a) 1800 (b) 180 (c) 18000
  37. 37.Best estimate of 90 × 66? (a) 63000 (b) 630 (c) 6300
  38. 38.Best estimate of 91 × 79? (a) 7200 (b) 720 (c) 72000
  39. 39.Best estimate of 579 + 284? (a) 700 (b) 900 (c) 1100
  40. 40.Best estimate of 49 × 21? (a) 10000 (b) 100 (c) 1000

Answer key

  1. 800
  2. 900
  3. 2000
  4. 5600
  5. 4000
  6. 700
  7. 1100
  8. 3600
  9. 800
  10. 700
  11. 900
  12. 4800
  13. 2400
  14. 3000
  15. 1000
  16. 8100
  17. 800
  18. 400
  19. 500
  20. 8100
  21. 2400
  22. 1000
  23. 800
  24. 4800
  25. 1400
  26. 600
  27. 2400
  28. 5600
  29. 1300
  30. 1400
  31. 2100
  32. 1000
  33. 1200
  34. 1800
  35. 400
  36. 1800
  37. 6300
  38. 7200
  39. 900
  40. 1000

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