4.89×9.9+4.89÷10和3.65÷0.25＋6.35×4的简便方法计算

4.89×9.9+4.89÷10
=4.89x9.9+4.89x0.1
=4.89x(9.9+0.1)
=4.89x10
=48.9
3.65÷0.25＋6.35×4
=3.65x4+6.35x4
=（3.65+6.35）x4
=10x4
=40