Regular expression to match digits and basic math operators

Question

I need a regular expression that will match 0-9, (,),+,-,* and /.

Answer 1

This works for mathematical expression with 4 decimal places:

^([-+]? ?(\d+(\.\d{0,4})?|\(\g<1>\))( ?[-+*\/] ?\g<1>)?)$

It's inspired in base of @ndnenkov answer.

I hope that can be useful for someone.