测算
cè suàn · HSK 7
to take measurements and calculate
📐🧮 测 measure + 算 calculate — survey first, then crunch the numbers
测 appears in 测量 (to measure) and 算 in 计算 (to compute). 测算 chains the two steps: gather raw data, then do the math on it.
测 — water radical 氵 + 则 (rule/standard)
测 combines the water radical 氵, hinting at meaning, with 则 (rule, standard), which also supplies the sound. Originally it referred to gauging the depth of water, then broadened to mean measuring, surveying, or testing in general.
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'.