← Rounding off and best estimate lesson New set →

Rounding Off and Estimation Worksheet

Mental maths lesson 15: Rounding off and best estimate · Set 433 · 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 311 + 147? (a) 400 (b) 600 (c) 200
  2. 2.Best estimate of 447 + 787? (a) 1000 (b) 1400 (c) 1200
  3. 3.Best estimate of 334 + 845? (a) 1100 (b) 900 (c) 1300
  4. 4.Best estimate of 48 × 17? (a) 100 (b) 10000 (c) 1000
  5. 5.Best estimate of 22 × 86? (a) 18000 (b) 1800 (c) 180
  6. 6.Best estimate of 58 × 88? (a) 54000 (b) 5400 (c) 540
  7. 7.Best estimate of 13 × 57? (a) 6000 (b) 600 (c) 60
  8. 8.Best estimate of 72 × 96? (a) 70000 (b) 7000 (c) 700
  9. 9.Best estimate of 290 + 842? (a) 1300 (b) 900 (c) 1100
  10. 10.Best estimate of 64 × 46? (a) 3000 (b) 30000 (c) 300
  11. 11.Best estimate of 578 + 153? (a) 600 (b) 1000 (c) 800
  12. 12.Best estimate of 177 + 157? (a) 200 (b) 600 (c) 400
  13. 13.Best estimate of 559 + 206? (a) 800 (b) 1000 (c) 600
  14. 14.Best estimate of 34 × 13? (a) 3000 (b) 30 (c) 300
  15. 15.Best estimate of 24 × 66? (a) 14000 (b) 1400 (c) 140
  16. 16.Best estimate of 625 + 784? (a) 1600 (b) 1400 (c) 1200
  17. 17.Best estimate of 93 × 36? (a) 36000 (b) 3600 (c) 360
  18. 18.Best estimate of 442 + 879? (a) 1500 (b) 1100 (c) 1300
  19. 19.Best estimate of 80 × 58? (a) 4800 (b) 48000 (c) 480
  20. 20.Best estimate of 42 × 26? (a) 1200 (b) 12000 (c) 120
  21. 21.Best estimate of 145 + 531? (a) 600 (b) 400 (c) 800
  22. 22.Best estimate of 92 × 34? (a) 27000 (b) 2700 (c) 270
  23. 23.Best estimate of 93 × 21? (a) 180 (b) 1800 (c) 18000
  24. 24.Best estimate of 97 × 58? (a) 600 (b) 6000 (c) 60000
  25. 25.Best estimate of 758 + 833? (a) 1600 (b) 1400 (c) 1800
  26. 26.Best estimate of 170 + 564? (a) 1000 (b) 600 (c) 800
  27. 27.Best estimate of 538 + 299? (a) 1000 (b) 600 (c) 800
  28. 28.Best estimate of 715 + 718? (a) 1600 (b) 1400 (c) 1200
  29. 29.Best estimate of 724 + 426? (a) 1100 (b) 900 (c) 1300
  30. 30.Best estimate of 313 + 666? (a) 1200 (b) 1000 (c) 800
  31. 31.Best estimate of 92 × 38? (a) 3600 (b) 36000 (c) 360
  32. 32.Best estimate of 425 + 259? (a) 500 (b) 900 (c) 700
  33. 33.Best estimate of 78 × 12? (a) 80 (b) 800 (c) 8000
  34. 34.Best estimate of 30 × 84? (a) 24000 (b) 2400 (c) 240
  35. 35.Best estimate of 46 × 16? (a) 1000 (b) 100 (c) 10000
  36. 36.Best estimate of 324 + 170? (a) 700 (b) 300 (c) 500
  37. 37.Best estimate of 46 × 14? (a) 500 (b) 5000 (c) 50
  38. 38.Best estimate of 770 + 843? (a) 1400 (b) 1800 (c) 1600
  39. 39.Best estimate of 78 × 83? (a) 6400 (b) 64000 (c) 640
  40. 40.Best estimate of 171 + 556? (a) 600 (b) 800 (c) 1000

Answer key

  1. 400
  2. 1200
  3. 1100
  4. 1000
  5. 1800
  6. 5400
  7. 600
  8. 7000
  9. 1100
  10. 3000
  11. 800
  12. 400
  13. 800
  14. 300
  15. 1400
  16. 1400
  17. 3600
  18. 1300
  19. 4800
  20. 1200
  21. 600
  22. 2700
  23. 1800
  24. 6000
  25. 1600
  26. 800
  27. 800
  28. 1400
  29. 1100
  30. 1000
  31. 3600
  32. 700
  33. 800
  34. 2400
  35. 1000
  36. 500
  37. 500
  38. 1600
  39. 6400
  40. 800

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