简便过程如下7.85×12+78.5×2.5+0.785×630=7.85×12+7.85×25+07.85×63=7.85×（12+25+63）=7.85×100=785望采纳，谢谢
7.85×12+78.5×2.5+0.785×630=7.85×12+7.85×25+7.85×63=7.85×(12+25+63)=7.85×100=785
