use the division sign when they should just use a fraction

There’s nothing wrong with using a Division sign, and anyone who thinks there is has forgotten the rules of Maths.

it is just visible no ambiguity

There’s NEVER any ambiguity. It’s what the rules of Maths are for!

a/b as in a over b

No, that’s a divided by b. (a/b) is a over b.

idk how to do fractions on the phone if you know tell me!

No need to, just use Brackets for Fractions.