added exercise 3

3_Simple_Calculation/Simple_Calculation.c

@@ -0,0 +1,32 @@
+#include <stdio.h>
+
+int main() {
+    // creating variables
+    int first = 0, second = 0, addition = 0, subtraction = 0, multiplication = 0, modulo = 0;
+    double division = 0;
+
+    // receiving numbers from user
+    printf("Please type in the first integer: ");
+    scanf("%i", &first);
+    printf("Please type in the second integer: ");
+    scanf("%i", &second);
+
+    // checking numbers
+    printf("Your input: %i and %i\nCalculating...\n\n", first, second);
+
+    // calculating
+    addition = first + second;
+    subtraction = first - second;
+    multiplication = first * second;
+    if (second != 0) {
+        division = first / second;
+    } else {
+        printf("\n\nError: Dividing by 0 is not allowed. Output will be 0.\n\n");
+    }
+    modulo = first % second;
+
+    // output of calculation
+    printf("The results are:\n+ = %i\n- = %i\n* = %i\n/ = %f\nmod = %i", addition, subtraction, multiplication, division, modulo);
+
+    return 0;
+}