=3.82*9.9+0.382+0.01=3.82(9.9+0.1)+0.01=3.82*10+0.01=38.2+0.01=38.21运用乘法分配律来来简便算法
3.82*10-0.382+0.392=38.2+0.01=38.21
3.82*10--0.382+0.392
