Took me a while to figure that ctr+= and ctr+- doesn't mean you pressing the +sign too.
I would have just written it as ctrl=. or ctrl-
ah, it's the = sign because you have to hold down the shift key for ctr+.
It also took me a while to figure out it's not section of the keyboard where numlock is.
Yes i know there is no equals sign there. Sometimes i am too lazy to put on my glasses.
I was hitting what i thought was an equals sign but was actually the minus sign.
Although i do wonder why not use the + and minus there.