I am using Excel 2007 and need some helping on a rounding formula. I would
like my cell to either round to the nearest whole num or ".5" of the number
but it needs to round down. For example:

5.1 would round to 5.0
5.4 would round to 5.0
5.5 would round to 5.5
5.7 would round to 5.5
5.9 would round to 5.5
6.0 would round to 6.0

I am using the Mround function but that rounds up so 5.8 and 5.9 rounds to
6.0 but I need them both to round to 5.5.

Any thoughts? Thanks!