84÷72÷36×21的简便算法
问题描述：
84÷72÷36×21的简便算法
答
=21*4/(72/36)*21
=21*21*2
=441*2
=882
答
84÷72÷36×21
= 84×21÷72÷36
= 7×12×3×7÷72÷36
= 7×36×7÷72÷36
= 7×7÷72
= 49/72