199.7+997.1+977.1-1997.71=?如何巧算?
问题描述：
199.7+997.1+977.1-1997.71=?如何巧算?
答
199.7+997.1+977.1-1997.71
=200-0.3+1000-2.9+1000-22.9-2000+2.29
=200-(0.3+25.8)+2.29
=200-26.1+2.29
=176.19
祝开心