#include<stdio.h> int main() { double a = 0.0; double b = 0.0; char c ='0'; scanf("%lf %c %lf",&a,&c,&b); { switch (c) { 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); break; c...