3.25*4.7+7.8
=3.25×（4.8-0.1）+7.8
=3.25×4.8-3.25×0.1+7.8
=3.25×4×1.2+7.8-0.325
=13×1.2+7.8-0.325
=15.6+7.8-0.325
=23.4-0.325
=23.075
3.25*4.7+7.8用简便方法怎么算
3.25*4.7+7.8
=3.25×（4.8-0.1）+7.8
=3.25×4.8-3.25×0.1+7.8
=3.25×4×1.2+7.8-0.325
=13×1.2+7.8-0.325
=15.6+7.8-0.325
=23.4-0.325
=23.075