I would like to truncate a cell as the user is entering data. All the number
formating techiques round the data up to the next value but I just want to
truncate it.

I see the formula =TRUNC(A1,4) will work but I cannot figure out how to use
the formula as a format. If the user is entering data into A1, it will
change A1's format to number when they enter data.

Any help will be appreciated.