When there is a percentage on the Excel form it comes out as a decimal with
numbers to the right when all I want is it to read 31%. I found from another
question/answer what seems to be how I fix this but I don't know where to put
this particular formula. What was written as a fix is,

Percentages

Frequently, percentages will display as decimals - e.g. 41% from the data
may display as 0.41354836739 when merged into Word. To display the decimal as
a percentage, you should create a calculated field e.g.:

{ ={ MERGEFIELD Amount} * 100\#"0%"}

From my understanding this will make it show up on the word document as 41%
instead of 0.41354836739. Where do I put this formula?

Thanks in advance for anyone's help.