Data Validation - ceiling and rounding

Hello,

I was hoping to include a cell where users can input any number that would round down to the nearest 10,000, and then cap off at 350,000.

I THINK this would be through a data validation but I'm unsure.

Any ideas?

if the cell where users enter a number is A1, then use this formula (change cell references if necessary):

=IF(A1>=350000,350000,FLOOR(A1,10000))

If you are saying that you want the user to input a number into a cell, and that number (in the same cell) will automatically be rounded down, that is only possible through the use of VBA which I cannot help with.
This is due to the fact that a cell can either contain a formula or a manually entered value, not both.

Doing this through the use of formulas is possible if the input cell and formula cell are two different cells.

For example, you can input the number into A1 then use this formula in B1:
=FLOOR(A1,10000)

You can then apply the following Data Validation to the input cell like this:
Select cell A1 > Data > Data Validation > Allow: Decimal > Data: less than > Maximum: 360000 > OK