Anzan
Anzan is mental arithmetic developed through soroban practice, using a visualized abacus to calculate without moving physical beads.
TokyoWaltz
Anzan is mental arithmetic developed through soroban practice, using a visualized abacus to calculate without moving physical beads.
Soroban is the Japanese abacus, a decimal calculating instrument used in commerce and education and still practised for arithmetic and mental calculation.