The story of how I became a genius with the abacus, and whether I can become a hero

Once I stepped into the world of the abacus, I became able to do mental arithmetic with 3-digit + 3-digit + 3-digit numbers.

Why do we shift digits in 'multiplication by long form'? —— Building floors and the 'two steps'

In the previous article, I dissected the true nature of division as 'subtraction (a process of reducing)' and explained that ...