adding all

add.c

@@ -0,0 +1,14 @@
+#include <stdio.h>
+void add() {    
+
+    int number1, number2, sum;
+
+    printf("Enter two integers: ");
+    scanf("%d %d", &number1, &number2);
+
+    // calculate the sum
+    sum = number1 + number2;      
+
+    printf("%d + %d = %d", number1, number2, sum);
+ //   return 0;
+}

main.c

@@ -0,0 +1,5 @@
+main(){
+   add();
+   sub();
+   mul();
+}

makefile

@@ -0,0 +1,10 @@
+ABHI.exe: add.o mul.o sub.o main.o
+	gcc -o ABHI.exe add.o mul.o sub.o main.o
+add.o:add.c
+	gcc -c add.c
+mul.o:mul.c
+	gcc -c mul.c
+sub.o:sub.c
+	gcc -c sub.c
+main.o:main.c
+	gcc -c main.c

mul.c

@@ -0,0 +1,14 @@
+#include <stdio.h>
+void mul() {
+    double a, b, product;
+    printf("Enter two numbers: ");
+    scanf("%lf %lf", &a, &b);  
+
+    // Calculating product
+    product = a * b;
+
+    // %.2lf displays number up to 2 decimal point
+    printf("Product = %.2lf", product);
+
+ //   return 0;
+}

sub.c

@@ -0,0 +1,14 @@
+#include<stdio.h>
+void sub(){
+  int num1, num2, difference;
+
+  //Asking for input
+  printf("Enter first number: ");
+  scanf("%d", &num1);
+  printf("Enter second number: ");
+  scanf("%d", &num2);
+
+  difference = num1 - num2;
+  printf("Difference of %d and %d is: %d", num1, num2, difference);
+ // return 0;
+}