換算
かんさん · kansan · JLPT N1 · noun
conversion
💴 換 kan = exchange + 算 san = calculate: kansan = calculating a conversion
換 (kan) means exchange or swap, and 算 (san) means count or calculate. Together they name the act of working out a conversion, such as yen into dollars.
算 — bamboo 竹 + abacus 具 (eye 目 + two hands 廾)
Originally depicted counting with bamboo rods on an abacus-like device. The top 竹 (bamboo) refers to the bamboo counting sticks used in ancient Chinese arithmetic, while the bottom shows hands manipulating them. The meaning broadened from 'to count' to 'to calculate' or 'to plan'.