← Rounding off and best estimate lesson New set →

Rounding Off and Estimation Worksheet

Mental maths lesson 15: Rounding off and best estimate · Set 529 · 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 176 + 568? (a) 800 (b) 1000 (c) 600
  2. 2.Best estimate of 370 + 843? (a) 1000 (b) 1400 (c) 1200
  3. 3.Best estimate of 49 × 94? (a) 4500 (b) 45000 (c) 450
  4. 4.Best estimate of 61 × 90? (a) 54000 (b) 5400 (c) 540
  5. 5.Best estimate of 177 + 252? (a) 300 (b) 700 (c) 500
  6. 6.Best estimate of 80 × 59? (a) 4800 (b) 480 (c) 48000
  7. 7.Best estimate of 369 + 615? (a) 1000 (b) 1200 (c) 800
  8. 8.Best estimate of 314 + 600? (a) 900 (b) 700 (c) 1100
  9. 9.Best estimate of 314 + 570? (a) 900 (b) 700 (c) 1100
  10. 10.Best estimate of 794 + 860? (a) 1700 (b) 1500 (c) 1900
  11. 11.Best estimate of 36 × 78? (a) 32000 (b) 3200 (c) 320
  12. 12.Best estimate of 44 × 26? (a) 120 (b) 12000 (c) 1200
  13. 13.Best estimate of 314 + 592? (a) 1100 (b) 700 (c) 900
  14. 14.Best estimate of 682 + 375? (a) 900 (b) 1300 (c) 1100
  15. 15.Best estimate of 267 + 316? (a) 800 (b) 600 (c) 400
  16. 16.Best estimate of 78 × 97? (a) 8000 (b) 80000 (c) 800
  17. 17.Best estimate of 69 × 79? (a) 560 (b) 56000 (c) 5600
  18. 18.Best estimate of 470 + 337? (a) 1000 (b) 800 (c) 600
  19. 19.Best estimate of 223 + 445? (a) 800 (b) 400 (c) 600
  20. 20.Best estimate of 89 × 41? (a) 36000 (b) 360 (c) 3600
  21. 21.Best estimate of 47 × 16? (a) 10000 (b) 1000 (c) 100
  22. 22.Best estimate of 299 + 232? (a) 500 (b) 300 (c) 700
  23. 23.Best estimate of 164 + 321? (a) 700 (b) 500 (c) 300
  24. 24.Best estimate of 404 + 853? (a) 1500 (b) 1100 (c) 1300
  25. 25.Best estimate of 93 × 66? (a) 63000 (b) 6300 (c) 630
  26. 26.Best estimate of 460 + 805? (a) 1300 (b) 1100 (c) 1500
  27. 27.Best estimate of 19 × 91? (a) 1800 (b) 180 (c) 18000
  28. 28.Best estimate of 68 × 39? (a) 2800 (b) 28000 (c) 280
  29. 29.Best estimate of 40 × 89? (a) 360 (b) 36000 (c) 3600
  30. 30.Best estimate of 452 + 527? (a) 1000 (b) 800 (c) 1200
  31. 31.Best estimate of 16 × 14? (a) 200 (b) 20 (c) 2000
  32. 32.Best estimate of 38 × 76? (a) 320 (b) 3200 (c) 32000
  33. 33.Best estimate of 432 + 192? (a) 400 (b) 800 (c) 600
  34. 34.Best estimate of 233 + 767? (a) 1000 (b) 800 (c) 1200
  35. 35.Best estimate of 219 + 233? (a) 400 (b) 600 (c) 200
  36. 36.Best estimate of 205 + 384? (a) 400 (b) 600 (c) 800
  37. 37.Best estimate of 658 + 399? (a) 1100 (b) 1300 (c) 900
  38. 38.Best estimate of 670 + 570? (a) 1500 (b) 1300 (c) 1100
  39. 39.Best estimate of 50 × 16? (a) 100 (b) 1000 (c) 10000
  40. 40.Best estimate of 14 × 40? (a) 4000 (b) 400 (c) 40

Answer key

  1. 800
  2. 1200
  3. 4500
  4. 5400
  5. 500
  6. 4800
  7. 1000
  8. 900
  9. 900
  10. 1700
  11. 3200
  12. 1200
  13. 900
  14. 1100
  15. 600
  16. 8000
  17. 5600
  18. 800
  19. 600
  20. 3600
  21. 1000
  22. 500
  23. 500
  24. 1300
  25. 6300
  26. 1300
  27. 1800
  28. 2800
  29. 3600
  30. 1000
  31. 200
  32. 3200
  33. 600
  34. 1000
  35. 400
  36. 600
  37. 1100
  38. 1300
  39. 1000
  40. 400

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