938+234-138+166 巧算

问题描述:

938+234-138+166 巧算

=(938-138)+(234+166)
=800+400
=1200

938+234-138+166
=938-138+166+234
=800+400
=1200

938+234-138+166
=(938-138)+(234+166)
=800+400
=1200