2.6*7.4+0.26*25+0.026*10 怎么巧算

问题描述:

2.6*7.4+0.26*25+0.026*10 怎么巧算
2.6*7.4+0.26*25+0.026*10
怎么巧算

原式
=2.6×7.4+0.26×25+0.26=2.6×7.4+0.26×(25+1)
=2.6×7.4+0.26×26
=2.6×7.4+2.6×2.6
=2.6×(7.4+2.6)
=2.6×10
=26