Scattergram

As you know I am crazy about the Japanese abacus (soroban). I have to undergo speed tests to progress from one level to the next. At yesterday’s International Soroban Competition, where I was the guest speaker, I learned that, at age 75, I have progressed from elementary to the 7th Kyu (it goes elementary, 10, 9, 8, 7, 6 …) faster than any past student of Abacus Maths. Here’s how I monitor and motivate my progress while practicing. It’s called a scattergram. I plot my time on the horizontal axis and my…