:=(×):(÷3) .
计算:321×654÷987÷654×987÷321= .
69+18+23+31+82= .
1.25×98+×+= .
计算:8+98+998+9998= 9+99+102+103+101+98= .
计算:64×12.5×0.25×0.05= .