C-Programming 25 - Building a Calculator with functions

calculator.c

#include <stdio.h>

//-- Function Signatures --//
int add(int a, int b);
int sub(int a, int b);
int mul(int a, int b);
int div(int a, int b);
float rdiv(int a, int b);

main() {
	int first;
	printf("Enter first number:");
	scanf("%d", &first);
	
	int second;
	printf("Enter second number:");
	scanf("%d", &second);
	
	printf("%d, %d, %d, %d, %f\n",
		add(first, second),
		sub(first, second),
		mul(first, second),
		div(first, second),
		rdiv(first, second)
	);
}

//-- Function definitions --//
int add(int a, int b){
	return a + b;
}

int sub(int a, int b){
	return a - b;
}

int mul(int a, int b){
	return a * b;
}

int div(int a, int b){
	return a / b;
}

float rdiv(int a, int b){
	return (float)a/b;
}