7.8×99+9.9×22简便运圆圆计旁塌腔世算,
7.8*99+9.9*22
=7.8*99+2.2*99
=(7.8+2.2)*99
=10*99
=990
7.8×0点者贺99+9点型谨九 =7.8×0.99+0.99×10 =0.99×(7.8+10) =(1-0.01)×17.8 =17.8-0.178 =17.622。首租派
7.8×99+3.9×2的渗没戚简便计算丛陵察拍 7.8×99+3.9×2 =7.8x99+7.8 =7.8x99+7.8x1 =7.8x(99+1) =7.8x100 =780
7.8×99+9.9×22
=99x(7.8+2.2)
=99x10
=990
=99*(7.8+2.2)=990