427+315-127+85简便运算为:=427+315-127+85=427-127+(315+85)=300+400=700
原式=427-127+(315+85)=300+400=700
427-127+(315+85)=300+400=700 凑整
427+315-127+85=427-127+315+85=300+400=700
427+315-127+85= (427-127)+(315+85)= 300 + 400 = 700