五年级练习题简便算法
问题描述:
五年级练习题简便算法
39.7*2.8+3.97*72 0.37*2400*0.25+3*8.75+2.825*30
答
39.7×(2.8+7.2)=397,0.37×200×(0.25×12)+3×8.75+3×28.75=(74+8.75+28.25)×3=111×3=333