← Rounding off and best estimate lesson New set →

Rounding Off and Estimation Worksheet

Mental maths lesson 15: Rounding off and best estimate · Set 384 · 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 165 + 149? (a) 500 (b) 100 (c) 300
  2. 2.Best estimate of 54 × 59? (a) 300 (b) 3000 (c) 30000
  3. 3.Best estimate of 814 + 225? (a) 1000 (b) 1200 (c) 800
  4. 4.Best estimate of 601 + 669? (a) 1100 (b) 1300 (c) 1500
  5. 5.Best estimate of 642 + 617? (a) 1000 (b) 1200 (c) 1400
  6. 6.Best estimate of 413 + 320? (a) 700 (b) 500 (c) 900
  7. 7.Best estimate of 517 + 825? (a) 1500 (b) 1300 (c) 1100
  8. 8.Best estimate of 528 + 236? (a) 700 (b) 900 (c) 500
  9. 9.Best estimate of 63 × 22? (a) 1200 (b) 12000 (c) 120
  10. 10.Best estimate of 400 + 123? (a) 300 (b) 700 (c) 500
  11. 11.Best estimate of 20 × 98? (a) 200 (b) 20000 (c) 2000
  12. 12.Best estimate of 151 + 566? (a) 600 (b) 800 (c) 1000
  13. 13.Best estimate of 828 + 174? (a) 1000 (b) 1200 (c) 800
  14. 14.Best estimate of 63 × 19? (a) 12000 (b) 1200 (c) 120
  15. 15.Best estimate of 129 + 681? (a) 1000 (b) 600 (c) 800
  16. 16.Best estimate of 36 × 31? (a) 12000 (b) 1200 (c) 120
  17. 17.Best estimate of 50 × 80? (a) 4000 (b) 400 (c) 40000
  18. 18.Best estimate of 12 × 69? (a) 70 (b) 7000 (c) 700
  19. 19.Best estimate of 36 × 17? (a) 8000 (b) 800 (c) 80
  20. 20.Best estimate of 773 + 190? (a) 800 (b) 1200 (c) 1000
  21. 21.Best estimate of 86 × 37? (a) 36000 (b) 360 (c) 3600
  22. 22.Best estimate of 208 + 494? (a) 900 (b) 700 (c) 500
  23. 23.Best estimate of 175 + 634? (a) 800 (b) 600 (c) 1000
  24. 24.Best estimate of 26 × 14? (a) 300 (b) 3000 (c) 30
  25. 25.Best estimate of 72 × 44? (a) 28000 (b) 2800 (c) 280
  26. 26.Best estimate of 40 × 22? (a) 800 (b) 80 (c) 8000
  27. 27.Best estimate of 47 × 49? (a) 2500 (b) 25000 (c) 250
  28. 28.Best estimate of 57 × 79? (a) 4800 (b) 48000 (c) 480
  29. 29.Best estimate of 177 + 440? (a) 400 (b) 800 (c) 600
  30. 30.Best estimate of 97 × 53? (a) 5000 (b) 50000 (c) 500
  31. 31.Best estimate of 36 × 74? (a) 280 (b) 2800 (c) 28000
  32. 32.Best estimate of 86 × 62? (a) 540 (b) 5400 (c) 54000
  33. 33.Best estimate of 80 × 53? (a) 4000 (b) 40000 (c) 400
  34. 34.Best estimate of 516 + 687? (a) 1400 (b) 1200 (c) 1000
  35. 35.Best estimate of 385 + 128? (a) 300 (b) 500 (c) 700
  36. 36.Best estimate of 64 × 38? (a) 240 (b) 2400 (c) 24000
  37. 37.Best estimate of 717 + 757? (a) 1500 (b) 1700 (c) 1300
  38. 38.Best estimate of 574 + 840? (a) 1400 (b) 1200 (c) 1600
  39. 39.Best estimate of 762 + 419? (a) 1200 (b) 1000 (c) 1400
  40. 40.Best estimate of 810 + 171? (a) 1200 (b) 1000 (c) 800

Answer key

  1. 300
  2. 3000
  3. 1000
  4. 1300
  5. 1200
  6. 700
  7. 1300
  8. 700
  9. 1200
  10. 500
  11. 2000
  12. 800
  13. 1000
  14. 1200
  15. 800
  16. 1200
  17. 4000
  18. 700
  19. 800
  20. 1000
  21. 3600
  22. 700
  23. 800
  24. 300
  25. 2800
  26. 800
  27. 2500
  28. 4800
  29. 600
  30. 5000
  31. 2800
  32. 5400
  33. 4000
  34. 1200
  35. 500
  36. 2400
  37. 1500
  38. 1400
  39. 1200
  40. 1000

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