Convert Text Data Entry fields to Numeric

Hey there,

I need to convert the pages of a content module that were created with Text Entry data fields into Numeric fields.

The fields won't be used to actually perform calculations, I just need the fields to have the mask that doesn't allow the user to enter anything other than numbers.

That said, each of the pages now contains a Text Entry field that has been converted into a Free Form question.

Can I just change the variables associated to the entry fields to numeric to perform this conversion?

Or, do I have to rebuild all the pages as numeric entry interactions? 

Thanks,

Eric