Shopping centre cafe

Several weeks ago, we found the Forge Shopping Centre, took quite a while for us to notice it given how long we've now been in central Glasgow. It's fairly linear with a fair range of stores, including an integral Asda at which we shopped this morning. There's a cafe in the concourse called Sisters which serves good food at a good price but enough of the staff are variously unfriendly that it isn't worth the mental cost. I get the impression that they'd prefer us not to bother them by ordering things. There is also quite a range of unlabelled dessert items, leaving me inclined to order only those things I can more precisely identify both to them and to myself.

Interest rate calculations

I was thinking how tricky interest rate calculations might be for institutions. One typically wants to quote an annual percentage but give interest more often than that. In terms of how the payments add up to the annual total, we certainly don't want that sum to be less than the quoted percentage but we would also rather it be as low as possible. Yet, when we pay interest, it's not like we pay exactly a twelfth root or whatever, or probably even calculate roots as precisely as we could, and we somehow round each payment to probably just a couple of places depending on the currency we're using. Further, absent withdrawals, the interest payments increase steadily due to compounding. In practice, I wonder how institutions deal with such payment calculations where each is rounded yet what matters is the sum of the payments.