#include <stdio.h> int main() { double a,b; char r; scanf("%lf%c%lf",&a,&r,&b); switch(r){ case '+':printf("%.4lf+%.4lf=%.4lf",a,b,a+b);break; case '-':printf("%.4lf-%.4lf=%.4lf",a,b,a-b);break; case '*':printf("%.4lf*%.4lf=%.4lf",a,b,a*b);br...