75.4-12.81-11.09-23.1=?的简便方法!

来源:学生作业学帮网 编辑:学帮网 时间:2024/06/05 21:44:40

75.4-12.81-11.09-23.1=?的简便方法!

原式=75.4-(12.81+11.09+23.1)
=75.4-(23.9+23.1)
=75.4-47
=28.4
411-299=411-300+1
=111+1
=112