Excel 2003

I'm trying to do a simple countif. In column A, I have...

A
010020
010020
010020
010020
10020
10020

In another cell, I have =COUNTIF(A:A,"010020"), which results in 6,
when I expect 4. It's counting the 10020 entries as well. I want an
exact match to the literal criteria I enter.

How do I do that?

Thanks,
Chuck