简便计算 9.7×（2.45--0.41） 34.58×97 101×26.9--1.25×26.9×0.8

9.7×（2.45--0.41）
=9.7*2.04
=9.7*(2+0.04)
=9.7*2+9.7*0.04
=(10-0.3)*2+(10-0.3)*0.04
=20-0.6+0.4-0.012
=20-0.212
=19.788
34.58×97
=34.58*(100-3)
=3458-103.74
=3354.26
101×26.9--1.25×26.9×0.8
=26.9*(101-1.25*0.8)
=26.9*(101-1)
=26.9*100
=2690