As you can see, I'm from South Africa. We use this convention (of the positive sign) in Gr. 12 in our country.

Anyway, I use a RichTextBox because I wrote a program for teachers without MS Word to set Maths papers quickly. As I said in the 3rd post, I don't have a problem any more with that. I guess the whole issue developed into a mathematics issue. It was interesting to hear opinions from other countries though.