905X99+905 13x10.2 两个算式如何简算?

问题描述:

905X99+905 13x10.2 两个算式如何简算?

905X99+905
=905×(99+1)
=905×100
=90500
13x10.2
=13x(10+0.2 )
=13x10+13x0.2
=130+2.6
=132.6