How to add rows and have the template's formula include the new cells on Numbers App?

Thanks, Camelot. I did solve the problem on my own. Short answer was to create a footer row and put the formula in that.

Longer story -- for anyone interested who might encounter this: I am not a Numbers user. I do have a cursory knowledge of Excel. I wanted to start a blood pressure log and figured I'd do it in Excel. I found a blood pressure template and started using it on my laptop. But I soon realized that I wanted to be able to access the log from my iPhone. My phone seemed unable to open the Excel file. (Perhaps there's an app for that -- I don't know.) But knowing Numbers existed, I (naively) thought I could just open the Excel file with Numbers and continue on. I did have to deal with some re-formatting issues and not knowing Numbers, I also had to learn a little about it. My posting here came about as I filled up the data rows, added more rows, and realized the formula showing the daily average of my readings wasn't updating. In the template, the formula lived in the same column as the data it was averaging. It was set up to average the range of cells pre-built into the template. (Average:: cell # to cell #), but what I needed was new rows to automatically extend the range. According to the knowledge base I looked at, the way to do so was to ask for an average of the whole column without specifying an end to the range. But in the template I'd ported over, that meant that the formula, living in the last cell of the column, was trying to include itself in the average and thus I was getting an error. That's the wall I hit and why I posted my question here. But continued research led me to the idea of putting the formula in the footer. I've not encountered a need to do that in Excel and haven't checked whether there's a comparable work flow there. But I do have my log working now. And will be more attentive if I ever again want to port an Excel template into Numbers.

Thanks again for responding.

Thanks for taking the time to reply, Camelot and SG.