← Rounding off and best estimate lesson New set →

Rounding Off and Estimation Worksheet

Mental maths lesson 15: Rounding off and best estimate · Set 249 · 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 716 + 870? (a) 1600 (b) 1400 (c) 1800
  2. 2.Best estimate of 163 + 132? (a) 500 (b) 100 (c) 300
  3. 3.Best estimate of 612 + 458? (a) 1300 (b) 900 (c) 1100
  4. 4.Best estimate of 725 + 818? (a) 1500 (b) 1300 (c) 1700
  5. 5.Best estimate of 82 × 58? (a) 480 (b) 48000 (c) 4800
  6. 6.Best estimate of 57 × 52? (a) 300 (b) 3000 (c) 30000
  7. 7.Best estimate of 397 + 538? (a) 900 (b) 700 (c) 1100
  8. 8.Best estimate of 23 × 76? (a) 160 (b) 1600 (c) 16000
  9. 9.Best estimate of 48 × 96? (a) 50000 (b) 500 (c) 5000
  10. 10.Best estimate of 386 + 383? (a) 600 (b) 800 (c) 1000
  11. 11.Best estimate of 532 + 736? (a) 1400 (b) 1200 (c) 1000
  12. 12.Best estimate of 90 × 36? (a) 360 (b) 36000 (c) 3600
  13. 13.Best estimate of 36 × 46? (a) 20000 (b) 200 (c) 2000
  14. 14.Best estimate of 46 × 87? (a) 4500 (b) 45000 (c) 450
  15. 15.Best estimate of 378 + 562? (a) 1200 (b) 1000 (c) 800
  16. 16.Best estimate of 68 × 80? (a) 560 (b) 56000 (c) 5600
  17. 17.Best estimate of 824 + 790? (a) 1800 (b) 1400 (c) 1600
  18. 18.Best estimate of 26 × 36? (a) 1200 (b) 12000 (c) 120
  19. 19.Best estimate of 60 × 51? (a) 300 (b) 30000 (c) 3000
  20. 20.Best estimate of 149 + 721? (a) 800 (b) 1000 (c) 600
  21. 21.Best estimate of 739 + 419? (a) 1100 (b) 1300 (c) 900
  22. 22.Best estimate of 54 × 61? (a) 30000 (b) 3000 (c) 300
  23. 23.Best estimate of 385 + 367? (a) 600 (b) 800 (c) 1000
  24. 24.Best estimate of 543 + 658? (a) 1400 (b) 1000 (c) 1200
  25. 25.Best estimate of 348 + 396? (a) 700 (b) 900 (c) 500
  26. 26.Best estimate of 130 + 688? (a) 1000 (b) 600 (c) 800
  27. 27.Best estimate of 300 + 147? (a) 600 (b) 400 (c) 200
  28. 28.Best estimate of 713 + 510? (a) 1200 (b) 1000 (c) 1400
  29. 29.Best estimate of 51 × 24? (a) 1000 (b) 10000 (c) 100
  30. 30.Best estimate of 547 + 634? (a) 1100 (b) 1300 (c) 900
  31. 31.Best estimate of 139 + 227? (a) 500 (b) 100 (c) 300
  32. 32.Best estimate of 36 × 37? (a) 160 (b) 16000 (c) 1600
  33. 33.Best estimate of 321 + 179? (a) 500 (b) 300 (c) 700
  34. 34.Best estimate of 698 + 373? (a) 1100 (b) 900 (c) 1300
  35. 35.Best estimate of 78 × 48? (a) 4000 (b) 40000 (c) 400
  36. 36.Best estimate of 76 × 38? (a) 32000 (b) 320 (c) 3200
  37. 37.Best estimate of 98 × 14? (a) 1000 (b) 10000 (c) 100
  38. 38.Best estimate of 41 × 16? (a) 8000 (b) 800 (c) 80
  39. 39.Best estimate of 92 × 26? (a) 27000 (b) 2700 (c) 270
  40. 40.Best estimate of 96 × 57? (a) 6000 (b) 600 (c) 60000

Answer key

  1. 1600
  2. 300
  3. 1100
  4. 1500
  5. 4800
  6. 3000
  7. 900
  8. 1600
  9. 5000
  10. 800
  11. 1200
  12. 3600
  13. 2000
  14. 4500
  15. 1000
  16. 5600
  17. 1600
  18. 1200
  19. 3000
  20. 800
  21. 1100
  22. 3000
  23. 800
  24. 1200
  25. 700
  26. 800
  27. 400
  28. 1200
  29. 1000
  30. 1100
  31. 300
  32. 1600
  33. 500
  34. 1100
  35. 4000
  36. 3200
  37. 1000
  38. 800
  39. 2700
  40. 6000

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