Constant sum "must total" validation option where the total equals the response to previous q?

Hello all,
I am building a survey where I need a specific validation option that I am having trouble figuring out. We will be asking the number of people their family, and then in the next question we want to use a constant sum question so participants can enter the number of people in their family that fall in to a specific age category. Below I have put a screenshot of what I these questions look like. I want the total for Q230 to have validation such that the total must equal the numeric response provided in Q228. Entering the piped text into the validation does not work.
I have found this: https://www.qualtrics.com/community/discussion/2715/constant-sum-must-total-question. I can get this to work but only if there are 7 response options in the table. The JS for the HOLD TOTAL question doesn't seem to be holding any information about the number of response to sum, at least not that I can tell. Does anyone have any ideas what the issue might be? Or have a different solution? Thank you!