Thanks for responding to my question.
I’ve tried adding the number function to custom-functions.php and when that didn’t work to functions.php, but it still doesn’t add anything to the output. The code put 0.00 in the corner of my wordpress editor page, but didn’t do anything to the field’s number. Am I adding the code to the wrong place? Do I have to put the field in the loop for it to work? Sorry, but I’m very much a novice when it comes to php.