C program calculater

#include <stdio.h>

int dclare;

int num1;

int num2;

void option()

{

printf("for ' + ' type 1\n for ' - ' type 2 \n for ' * ' type 3\n");

scanf("%d", &dclare);

} 

void option2()

{

switch (dclare)

{

case 1:

printf("=%d", num1 + num2);

break;

case 2:

printf("=%d", num1 - num2);

break;

case 3:

printf("=%d", num1 * num2);

break;

default:

printf("enter again");

break;

}

}

int main()

{

printf("\nenter the first number\n>>");

scanf("%d", &num1);

printf("enter the second number\n>>");

scanf("%d", &num2);

option();

option2();

main();

}