Quick math calc on any buffer

[Rodrigo Lazo]

Hi all,

Is there a way to compute a math expression on any buffer? I mean, if I
have a buffer with the following expression

2 + 3 

I want to mark the region and compute the result

2 + 3 = 5

It doesn't seems too hard to do, I've looked on calculator.el for a
"computing" function I can call but I didn't find it. 

Regards

-- 

Rodrigo Lazo (rlazo)