ㄒㄧㄣxīnㄙㄨㄢˋsuàn

  1. 計劃籌劃·潘岳荊州〉:多才洽聞毫末心算無垠。」

  2. 紙筆算盤計算機器具專用心思計算方法默算筆算

mental arithmetic, to calculate in one's head, planning, preparation
techniques de calcul mental
Kopfrechnen (S)​, kopfrechnen (V)​