Power cards: Why?

[WhatGravitas]

...given that A1 is a 1m x 1m sheet of paper and getting smaller proportionally from there (look up paper sizes on wikipedia).

Nitpick: It's an area of a square meter, in the ratio one to root two, hence by halving the length of the wide side, you get a sheet of the next smaller size.

Cheers, LT.