Hi GrannyDaisy - glad you liked the chops, easy wasn't it?
I make loads more crumble mix than I need and put the rest (portion sized) into marg tubs and stick them in the freezer. Keeps for ages and handy for when you need another crumble.
When you run out, just make another 'batch'.
I personally put the sugar in with the flour and fat, the roughness of the sugar makes it quicker to blend the fat somehow.