42.8*6.3是不是应该是42.3*6.3呀42.3*6.3+4.23*25+0.423*120抱歉.我打错了42.3*6.3=4.23*10*6.3=4.23*630.423*120=4.23*12所以42.3*6.3+4.23*25+0.423*120=4.23*63+4.23*25+4.23*12=4.23*（63+25+12）=4.23*100=423