Americans either write a single vertical stroke or an upward hook with a horizontal base line. Europeans (well, Germans and Hungarians to my own knowledge) write just the upward hook - to distinguish this from a 7, they cross the seven.
This font rendered fours (Chrome on Win 7) without the horizontal bar, leaving something that looked like a 1, to me.
This font rendered fours (Chrome on Win 7) without the horizontal bar, leaving something that looked like a 1, to me.