Bug for small numbers in Calculator application

Bug in Utilities->Calculator (v10.7.1 in OS X 10.7.4):

I searched the site (and the internet) for discussion about this topic, and was surprised to find no results.

The Calculator application which comes with OS X treats numbers <= 1e15 as ZERO.

Typing in

1 -> EE -> 15 -> 1/x results in "0"

1 -> EE -> 15 -> = also gives "0"

To prove that this is not just a display problem:

1 -> EE -> 15 -> +/- -> 1/x results in "Not a number"

It seems the application is incapable of storing small numbers.

This should not be a typical 'machine epsilon' problem (which arises in addition) nor is it just a display problem, nor should it be a float-vs-double datatype problem. Even floats can be stored which are much smaller than this. The error is not with computer or the OS, it is the implementation inside the Calculator app.

This needs addressing.