Question
Is it possible to store the variable width of a node and use that width to calculate the text width of another node in TikZ?
Example
I have a list of similar nodes side-by-side (inline, not overlaid). Let's call the left column of nodes "A" and the right column of nodes "B". Column A nodes contain a number (counter variable, which means the node gets wider at each digit carry-over). Column B nodes should have some text width minus the text width of the corresponding node in column A.
get width of node A =
\fontsize{50}{60}\selectfont\countervalue{}text width of node B = (\textwidth) - (width of node A)
I think the answer I am looking for is hidden somewhere in this answer.

\xin your example, but I am still unsure of what\xis and where it came from. I expected to see the width of the first node being set somewhere (like in a pgf variable). – Jonathan Komar Feb 08 '15 at 21:55Ais the distance between itswestandeastanchors. In the example above, the point\p1is calculated by subtractingA.westfromA.east(@percusse used thea-\jas node name instead ofA, but the idea is the same). To refer to the x-coordinate of point\p1, you can use\x1, which is equal to the x-coordinate ofA.eastminus the x-coordinate ofA.west. This difference is exactly the width of nodeA. – Herr K. Feb 08 '15 at 22:21