2008: How prevent automatic, unwanted ".0" before numbers?

In Excel 2008 (v. 12.1.0) (OS 10.5.3), if I open a new worksheet and type a
number for later calculation, for instance, "2", it automatically enters
as
".02"

The only way I can enter a number without the application automatically
placing the ".0" before it is to first select/type the equal sign.  Do I
really need to use this workaround?

I've been working with Excel spreadsheets for many years without this
problem.  Is this a 12.1.0 bug?  If not, what am I forgetting or missing?

Respectfully, Norm