day 65 of 100daysians: abacus (suanpan)

an archaic skill, given the invention of calculators and the godfather of them all, the TI-83.  

i thought this would be a cool extracurricular after chinese school. not the case. since i was also doing kumon, which preaches mental math and agility, i found counting with beads infuriating and counter-productive.

you can do all 4 operations, square root, and cube root with an abacus by moving beads up and down. you only count the value of the beads touching the middle beam. the cranmer abacus is used today to teach the blind to do math, which is pretty cool.