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Sea, beer and a calculator.
(feddit.uk)
A random shot of my calculator 5000 miles from home while I enjoy a beer near the Pacific. We had been discussing how much water was on earth and what size of a ball it would make. I have no affiliation with the brewing company so apologies for the product placement.
You do have to remind yourself at the beginning that you're using RPN, but after a while it feels a bit like working sums out on paper.