formatting data in a field

[David Coker]

Hello folks,
I seem to continually get hung up in areas that should be fairly simple by now.
Here is the latest that I find myself banging my head over...

<sigh>
Lets say that I have two fields calculated where the sum contains
something like 3.1666 as an example.
What would be the proper way to format the display field as 3.16 ?
</sigh>

I've tried using both "format" and "numberFormat" in various ways
without any luck so far
As always, I certainly appreciate any and all help I get.

David C.