This is not quite accurate. The first few columns were reserved for an optional numeric statement label that could then be used as a target for an IF or GOTO st

This is not quite accurate. The first few columns were reserved for an optional numeric statement label that could then be used as a target for an IF or GOTO statement (and we used lots of those!) Labels did not have to be in numerically increasing order. On the other hand, the last few columns of the card were ignored by the compiler, and could indeed be used to hold numerical values. These could be used to sort the deck of cards if you dropped it. The choice of numerical values in this column was not trivial because of the way programs were edited to fix bugs: you manually removed some cards and inserted new ones into the deck. You never repunched the whole program.