「 4MX93 」 一覧 Without teaching, a 3rd grade DONGURI child of primary school solves a problem of the simultaneous equations! 2018/10/28 -Donguri articles in English 4MX93, donguri, MATH, primaria, primary, PROBLEM, problema A 3rd grade donguri child of primary school solves here one of the problems of the simultaneous equa …