简便计算3.14×（6÷2）+3.14×2×23.14×（6÷2）+3.14×2×2=3.14x3+3.14x4=3.14x(3+4)=3.14x7=3.14x(10-3)=3.14x10-3.14x3=31.4-9.42=21.98
