# Why do some people put a dash in the Number 7?

Question:I didn't learn this in school. when did people start doing this?

Europeans and U.S. military personnel place a slash through the number 7 to prevent confusing it with the Arabic number 1.

In military communications this practice has been with us since World War II. When Germans write a number 1 it resembles a 7 for most Americans.
its a German thing,
a throw back to the middle ages when numbers often resembled letters.
It also kinda looks cool!!
Just recently..it's the cool new thing to do! Ja!
This comes from Europe, where the dash is an official part of the number seven. It's to prevent confusion with the number 'one' which, in Europe, has the little slanted line at the top, and that is sometimes mistaken for a carelessly written 'seven' so the slash through the stem of the seven clearly distinguishes the two.
Many people put a dash in the number 7 because their 7's look like 1's. It is simply to avoid the frustration of squinting to decipher the writing or making some form of error because of it. Many people (myself included) also put a dash in the letter Z when using it in equations with numbers to assure that it is not mistaken for the number 2.

I don't know when it began, but it sure did make Algebra easier!
It is done for the same reason a diagonal slash is put through a 0, so it is not mistaken for a letter. Many people see a 7 and may thing it is a capital or the number 1, especially if the letters are written with serifs.
I'm actually not sure. I started crossing my sevens in fifth grade, because I absolutely adored my teacher, who crossed his sevens. In an effort to impress him, I started crossing my sevens also. Years later, it has become a habit, and I think they look better!
7s and 1s.

I do the same with my Z's, as they look like my 2's
I think it is the French way.