← Rounding off and best estimate lesson New set →

Rounding Off and Estimation Worksheet

Mental maths lesson 15: Rounding off and best estimate · Set 953 · 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 738 + 633? (a) 1500 (b) 1100 (c) 1300
  2. 2.Best estimate of 16 × 82? (a) 16000 (b) 160 (c) 1600
  3. 3.Best estimate of 18 × 83? (a) 16000 (b) 1600 (c) 160
  4. 4.Best estimate of 66 × 68? (a) 4900 (b) 490 (c) 49000
  5. 5.Best estimate of 707 + 279? (a) 800 (b) 1200 (c) 1000
  6. 6.Best estimate of 89 × 91? (a) 81000 (b) 8100 (c) 810
  7. 7.Best estimate of 28 × 77? (a) 240 (b) 2400 (c) 24000
  8. 8.Best estimate of 197 + 749? (a) 700 (b) 1100 (c) 900
  9. 9.Best estimate of 222 + 375? (a) 600 (b) 800 (c) 400
  10. 10.Best estimate of 136 + 677? (a) 600 (b) 800 (c) 1000
  11. 11.Best estimate of 40 × 30? (a) 120 (b) 1200 (c) 12000
  12. 12.Best estimate of 36 × 31? (a) 1200 (b) 120 (c) 12000
  13. 13.Best estimate of 81 × 94? (a) 7200 (b) 72000 (c) 720
  14. 14.Best estimate of 318 + 683? (a) 1200 (b) 800 (c) 1000
  15. 15.Best estimate of 133 + 540? (a) 600 (b) 800 (c) 400
  16. 16.Best estimate of 79 × 70? (a) 560 (b) 56000 (c) 5600
  17. 17.Best estimate of 328 + 838? (a) 900 (b) 1100 (c) 1300
  18. 18.Best estimate of 226 + 375? (a) 600 (b) 800 (c) 400
  19. 19.Best estimate of 257 + 253? (a) 600 (b) 400 (c) 800
  20. 20.Best estimate of 567 + 354? (a) 800 (b) 1000 (c) 1200
  21. 21.Best estimate of 612 + 838? (a) 1400 (b) 1600 (c) 1200
  22. 22.Best estimate of 40 × 73? (a) 2800 (b) 28000 (c) 280
  23. 23.Best estimate of 19 × 12? (a) 200 (b) 20 (c) 2000
  24. 24.Best estimate of 19 × 58? (a) 1200 (b) 120 (c) 12000
  25. 25.Best estimate of 50 × 23? (a) 100 (b) 10000 (c) 1000
  26. 26.Best estimate of 86 × 34? (a) 27000 (b) 270 (c) 2700
  27. 27.Best estimate of 36 × 40? (a) 16000 (b) 1600 (c) 160
  28. 28.Best estimate of 404 + 140? (a) 300 (b) 500 (c) 700
  29. 29.Best estimate of 256 + 593? (a) 1100 (b) 700 (c) 900
  30. 30.Best estimate of 46 × 56? (a) 3000 (b) 30000 (c) 300
  31. 31.Best estimate of 44 × 50? (a) 200 (b) 20000 (c) 2000
  32. 32.Best estimate of 90 × 80? (a) 72000 (b) 7200 (c) 720
  33. 33.Best estimate of 543 + 849? (a) 1300 (b) 1100 (c) 1500
  34. 34.Best estimate of 36 × 33? (a) 1200 (b) 12000 (c) 120
  35. 35.Best estimate of 93 × 28? (a) 27000 (b) 2700 (c) 270
  36. 36.Best estimate of 43 × 40? (a) 16000 (b) 160 (c) 1600
  37. 37.Best estimate of 712 + 641? (a) 1100 (b) 1500 (c) 1300
  38. 38.Best estimate of 568 + 229? (a) 1000 (b) 600 (c) 800
  39. 39.Best estimate of 16 × 81? (a) 1600 (b) 160 (c) 16000
  40. 40.Best estimate of 36 × 16? (a) 800 (b) 8000 (c) 80

Answer key

  1. 1300
  2. 1600
  3. 1600
  4. 4900
  5. 1000
  6. 8100
  7. 2400
  8. 900
  9. 600
  10. 800
  11. 1200
  12. 1200
  13. 7200
  14. 1000
  15. 600
  16. 5600
  17. 1100
  18. 600
  19. 600
  20. 1000
  21. 1400
  22. 2800
  23. 200
  24. 1200
  25. 1000
  26. 2700
  27. 1600
  28. 500
  29. 900
  30. 3000
  31. 2000
  32. 7200
  33. 1300
  34. 1200
  35. 2700
  36. 1600
  37. 1300
  38. 800
  39. 1600
  40. 800

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