Oh I feel so dense ,please forgive me.
Realise that I've somehow been confusing the UCAS tarif ( though I do vaguely get the concept of UMS ) with results at AS and A2.
But Lillymaid now I've looked again at son's marks at AS ,I can see that they are out of 300.
so wouldn't figures you give for A2 ,eg 480 for an A ,be 600 for an A ???
Or have I got it all wrong again ?