4.7×7.8+0.47×22 求怎么巧算

问题描述:

4.7×7.8+0.47×22 求怎么巧算

4.7x7.8+0.47x10x2.2
=4.7x7.8+4.7x2.2
=4.7x(7.8+2.2)
=4.7x10
=47