I distribute a worksheet to many users to supply standardized data inputs and
it includes a lot of validation and cell protection to prevent creativity.
Someone beat my data validation rule for a cell by simply copying & pasting
another cell over it.

In simple terms:
Valid entries for Column A (using a list/dropdown) are odd numbers 1, 3, 5,
7, 9
Valid entries for Column B (using a list/dropdown) are even numbers 2, 4, 6, 8

Copying and pasting cell A1 into B1 allowed someone to get an odd number
into B1.

Additional cell protection in A&B keeps jumping into my mind, but each time
I think about it, I realize protection runs contrary to allowing data input.
Or does it ?

Any suggestions for keeping copy/pasters from getting invalid data into
Column B?

TIA.