Changing a dynamic data text box to have an interger value

Hey team,
I have a page I am creating that takes a series of numerical inputs (eg. wall perimeter and square footage). I have then used dynamic data in text boxes to multiply those input numbers to get calculations such as area, volume etc. This is shown in the screenshot.

What I am trying to do is then reference those numerical values in the text boxes so I can continue to do further calculations in different columns (shown under Subtotal Heat Loss). Since the text box shows up only as text, there is no way for me to assign a numerical value, even though the result is a number.

Is this even possible with a text box, or do I need to be using a different element to display dynamic data?

Thanks in advance!

Display as text at end of calculation should help