Roland’s crossword puzzle this morning had a reference to chisenbop, a manual reckoning system where you use your fingers like the beads of an abacus. I hadn’t heard about chisenbop for decades, not since I saw a TV ad for a book that would teach your kids how to count on their fingers. I think Fred MacMurray was the celebrity spokesman, but I could be wrong.
And I was thus reminded of Jakow Trachtenberg’s Speed System of doing multiplication and other arithmetic without pencil and paper. Somebody told me about it when I was a kid, I checked the book out of the library and devoured it. I don’t really remember any of it, except that multiplying by 12 was especially easy. Trachtenberg developed the system while he was held in a concentration camp in World War II and, if you will, didn’t have anything better to do with his time. The book is still in print.