3.14*0.68+31.4*0.032=3.14*0.68+3.14*0.32=3.14*(0.68+0.32)=3.14*1=3.14
3.14 X0.68十31.4X0.032=3.14x(0.68+10x0.032)=3.14
3.14 X0.68十31.4X0.032=3.14x(0.68+10x0.032)=3.14*1=3.14