← Rounding off and best estimate lesson New set →

Rounding Off and Estimation Worksheet

Mental maths lesson 15: Rounding off and best estimate · Set 853 · 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 86 × 54? (a) 45000 (b) 4500 (c) 450
  2. 2.Best estimate of 56 × 30? (a) 18000 (b) 1800 (c) 180
  3. 3.Best estimate of 51 × 52? (a) 2500 (b) 25000 (c) 250
  4. 4.Best estimate of 704 + 534? (a) 1400 (b) 1200 (c) 1000
  5. 5.Best estimate of 151 + 281? (a) 300 (b) 700 (c) 500
  6. 6.Best estimate of 26 × 53? (a) 15000 (b) 1500 (c) 150
  7. 7.Best estimate of 135 + 670? (a) 600 (b) 800 (c) 1000
  8. 8.Best estimate of 62 × 96? (a) 60000 (b) 600 (c) 6000
  9. 9.Best estimate of 818 + 327? (a) 1300 (b) 1100 (c) 900
  10. 10.Best estimate of 32 × 50? (a) 15000 (b) 150 (c) 1500
  11. 11.Best estimate of 719 + 197? (a) 900 (b) 1100 (c) 700
  12. 12.Best estimate of 32 × 19? (a) 60 (b) 600 (c) 6000
  13. 13.Best estimate of 147 + 739? (a) 800 (b) 1000 (c) 600
  14. 14.Best estimate of 549 + 149? (a) 600 (b) 400 (c) 800
  15. 15.Best estimate of 47 × 41? (a) 2000 (b) 20000 (c) 200
  16. 16.Best estimate of 84 × 60? (a) 48000 (b) 480 (c) 4800
  17. 17.Best estimate of 225 + 481? (a) 700 (b) 900 (c) 500
  18. 18.Best estimate of 758 + 529? (a) 1300 (b) 1100 (c) 1500
  19. 19.Best estimate of 86 × 70? (a) 630 (b) 6300 (c) 63000
  20. 20.Best estimate of 517 + 135? (a) 800 (b) 600 (c) 400
  21. 21.Best estimate of 512 + 486? (a) 1200 (b) 800 (c) 1000
  22. 22.Best estimate of 76 × 49? (a) 4000 (b) 40000 (c) 400
  23. 23.Best estimate of 46 × 86? (a) 450 (b) 45000 (c) 4500
  24. 24.Best estimate of 56 × 76? (a) 4800 (b) 48000 (c) 480
  25. 25.Best estimate of 286 + 241? (a) 300 (b) 500 (c) 700
  26. 26.Best estimate of 79 × 70? (a) 56000 (b) 560 (c) 5600
  27. 27.Best estimate of 629 + 162? (a) 800 (b) 1000 (c) 600
  28. 28.Best estimate of 59 × 32? (a) 180 (b) 1800 (c) 18000
  29. 29.Best estimate of 86 × 66? (a) 63000 (b) 630 (c) 6300
  30. 30.Best estimate of 67 × 54? (a) 35000 (b) 350 (c) 3500
  31. 31.Best estimate of 625 + 592? (a) 1400 (b) 1200 (c) 1000
  32. 32.Best estimate of 641 + 153? (a) 600 (b) 1000 (c) 800
  33. 33.Best estimate of 76 × 30? (a) 24000 (b) 240 (c) 2400
  34. 34.Best estimate of 447 + 193? (a) 400 (b) 600 (c) 800
  35. 35.Best estimate of 509 + 784? (a) 1100 (b) 1300 (c) 1500
  36. 36.Best estimate of 265 + 157? (a) 700 (b) 500 (c) 300
  37. 37.Best estimate of 77 × 47? (a) 400 (b) 40000 (c) 4000
  38. 38.Best estimate of 38 × 79? (a) 3200 (b) 320 (c) 32000
  39. 39.Best estimate of 71 × 24? (a) 140 (b) 1400 (c) 14000
  40. 40.Best estimate of 281 + 833? (a) 1100 (b) 900 (c) 1300

Answer key

  1. 4500
  2. 1800
  3. 2500
  4. 1200
  5. 500
  6. 1500
  7. 800
  8. 6000
  9. 1100
  10. 1500
  11. 900
  12. 600
  13. 800
  14. 600
  15. 2000
  16. 4800
  17. 700
  18. 1300
  19. 6300
  20. 600
  21. 1000
  22. 4000
  23. 4500
  24. 4800
  25. 500
  26. 5600
  27. 800
  28. 1800
  29. 6300
  30. 3500
  31. 1200
  32. 800
  33. 2400
  34. 600
  35. 1300
  36. 500
  37. 4000
  38. 3200
  39. 1400
  40. 1100

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