If I took all the numbers from one to one billion:

- How many of them contain at least one '1'?
- If I wrote them out in one long line, how many 1 digits would there be?

1. The total number of posiive integers from 1 to 1 billion containing at least one "1" is 612,579,512.

2, Total number of 1's in all the integers from 1 to i billion is 900,000,001.