I do. My writing isn’t the greatest. I wasn’t taught it, but one of my professors did them that way and on a math test I got a problem wrong when in one of my calculations I got a 7 mixed up with a 2. I also do open top 4’s.
American born and raised. I just prefer to eliminate all ambiguities. Also, since arthritis is taking its toll on me, I have the handwriting of a psychopath, so it’s kind of necessary.
I got into the habit of slashing zeros at the same time. This was reinforced by getting a job in computers. But I (mostly) broke the habit after visiting Sweden, where Ø is a letter.
After I became a CS major, I changed the way I write numerals. Crossed sevens and zeros, single stroke fours (like the Fantastic Four), twos without a loop (like a typewritten 2), and two separate circles for eights. I also cross my Zs (to distinguish them from 2s).
Closed 4s since graphics class in high school. Crossed 7s since living in Germany for three years. Also, it keeps someone from confusing a hastily written 7 with a one.
Since the majority of people just use a straight up-down line for a one these days without any attempt to be fancy, I’m not sure I understand the point of crossed sevens. OTOH, some of my numbers are odd looking anyway. You know how an open 4 has that little bit sticking out on the right? Mine don’t, they stop at the straight up-down part. And The up-down part of a 5? I don’t do that either, but have an angled line off the loop. I’ve only ever had one person complain, though. (she thought it was remotely possible *someone *might think my 5 was a 3, not that she had any problem herself telling them apart.)