I have 200 vectors that I want to sum. Each vector has its own currency and there are 2 basic ways of looking at the vectors (sum by X, sum by Y, grand total).

I want to add check sum so that I can tell at a glance that I have all of the vectors, I haven't missed any and I haven't double counted any. I need to be able to do this when I sum over X, over Y and in total.

What is the best way to construct such a check sum?