[bumbledraven]

Doerfler's _ Dead Reckoning: Calculating Without Instruments _ (pages 47-73) deals extensively with this issue. https://archive.org/stream/deadreckoningcal00doer#page/46/mo...

[dahart]

Picked up a copy of that book a few years ago, I think because of a comment I read here on HN. It is fantastic for learning various mental and pencil/paper techniques. Having read it helped me out with a few problems on Project Euler.