Extracting signal digit numbers from a set of signal code with several digits

Source Code :

#include<stdio.h>

#include<conio.h>

void main(void)

{

int no,a,b,c,d,e,f,sum14,sum12,sum13,pro12,pro14,pro13,sub12,sub13,sub14;

float div12,div13,div14;

clrscr();

printf("Enter a 4 digit number:");

scanf("%d",&no);

printf("\n\t Extracing singal digits from a code");

printf("\n\t-------------------------------------");

a=(no/1000);

b=(no%1000);

c=(b/100);

d=(b%100);

e=(d/10);

f=(d%10);

sum14=(a+f);

sum12=(a+c);

sum13=(a+e);

pro14=(a*f);

pro12=(a*c);

pro13=(a*e);

sub14=(a-f);

sub12=(a-c);

sub13=(a-e);

div13=(a/e);

div12=(a/c);

div14=(a/f);

printf("\nThe first number is : %d",a);

printf("\nThe second number is : %d",c);

printf("\nThe third number is : %d",e);

printf("\nThe Fourth number is : %d",f);

printf("\n\nThe sum of the first and the last numbers are : %d",sum14);

printf("\nThe sum of the first and the second numbers are : %d",sum12);

printf("\nThe sum of the first and the third numbers are : %d",sum13);

printf("\n\nThe product of the first and the last numbers are : %d",pro14);

printf("\nThe product of the first and the second numbers are : %d",pro12);

printf("\nThe product of the first and the third numbers are : %d",pro13);

printf("\n\nThe subtract of the first and the last numbers are : %d",sub14);

printf("\nThe subtract of the first and the second numbers are : %d",sub12);

printf("\nThe subtract of the first and the third numbers are : %d",sub13);

printf("\n\nThe devide of the first and the last numbers are : %.2f",div14);

printf("\nThe devide of the first and the second numbers are : %.2f",div12);

printf("\nThe devide of the first and the third numbers are : %.2f",div13);

getch();

}