56.5×9.9+56.5的巧算_数学解答

56.5×9.9+56.5的巧算

人气：490 ℃　时间：2020-05-02 06:37:00

解答

56.5×9.9+56.5
=56.5×（10-0.1）+56.5
=56.5×10-0.1×56.5+56.5
=565-5.65+56.5
=565+50.85
=615.85