Add punctuation: The next question he asked himself in January 1874 was whether the unit square could be mapped into a line of unit length with a 11 correspondence of points on each
A: The next question he asked himself, in January 1874, was whether the unit square could be mapped into a line of unit length with a 1-1 correspondence of points on each.

Add punctuation: Translation of the website Dumbolf
A: Translation of the website - Dumbolf

Add punctuation: The statistics say that 90 of all hacker attacks start with an email The remaining 10 are a number of other approaches such as a hacked website port scan etc
A:
The statistics say that 90% of all hacker attacks start with an email. The remaining 10% are a number of other approaches, such as a hacked website, port scan, etc.