I've read over the postgresql docs but I'm still wondering about this one.

I have several numeric data type fields set at:

Now, would this mean a total number size of 12 digits with 2 decimal places? Or the other way around?

I'm using it for a dollar amount. When I enter 123.23 into a form field and it get's saved, I then look at the raw tables and it shows up as 123.230 But, I'm only needing 123.23 and am thinking this may cause problems down the road for calculations on these numbers.