Using - C
  
 Source Code
  

    
#include<stdio.h>

void main() {
  char ch;
  int num1, num2;
  input: 
  printf("Enter Expression:  ");
  scanf("%d %c %d", &num1, &ch, &num2);
  
  switch(ch)
  {
    case '+': printf("%d + %d = %d",num1, num2, (num1 + num2));
          break;
    case '-': printf("%d - %d = %d",num1, num2, (num1 - num2));
          break;
    case '*': printf("%d X %d = %d",num1, num2, (num1 * num2));
          break;
    case '/': printf("%d / %d = %.2f",num1, num2, (num1 / (float)num2));
          break;
    default:  system("cls");
          printf("Enter a valid expression! \n\n");
          goto input;
  }

}
    

Enter Expression:  5*6
5 X 6 = 30

        
Using - C++
        
 Source Code
        

        
#include<iostream>
using namespace std;

int main() {
  char ch;
  int num1, num2;
  input:
  cout<< "Enter Expression:  ";
  cin>> num1 >> ch >> num2;
  
  switch(ch) 
  {
    case '+': cout<< num1 << " + " << num2 << " = " << (num1 + num2) << endl;
          break;
    case '-': cout<< num1 << " - " << num2 << " = " << (num1 - num2) << endl;
          break;
    case '*': cout<< num1 << " X " << num2 << " = " << (num1 * num2) << endl;
          break;
    case '/': cout<< num1 << " / " << num2 << " = " << (num1 / (float)num2) << endl;
          break;
    default:  system("cls");
          cout<< "Enter a valid expression! \n"<< endl;
          goto input;
  } 
      
    return 0;
  }

Enter Expression:  5/2
5 / 2 = 2.5