feat: Add FunctionsCC4 class with calculateSum and average calculation

WHAT the code does:
- Defines a `FunctionsCC4` class with a static method `calculateSum(int num1, int num2)`.
- `calculateSum()` returns the sum of two integers.
- In `main()`:
  - Calls `calculateSum(3, 4)` and stores result in `sum`.
  - Computes average as `sum / 2`.
  - Prints the average.

WHY this matters:
- Demonstrates **storing return values** in variables for further use.
- Shows chaining of operations: using method output to calculate another result.
- Reinforces return values vs intermediate computation inside main.

HOW it works:
1. `calculateSum(3, 4)` → returns `7`.
2. `sum = 7`.
3. `avg = 7 / 2` → integer division gives `3`.
4. Prints `3`.

Tips & gotchas:
- Since `avg` is `int`, fractional parts are truncated.
  → Use `double` for more accurate averages (`(double) sum / 2`).
- `int sum = 0;` is redundant before assignment — can be simplified.
- Method name could be generalized to `add()` if reused in other contexts.

Use-cases:
- Educational example for **return values + further calculations**.
- Basis for programs needing averages, totals, or aggregates.
- Useful for explaining integer division vs floating-point division in Java.
- Starter code for building math utility libraries.

Short key: class-functions cc4-sum-average.

Signed-off-by: https://github.com/Someshdiwan <[email protected]>

Author: Someshdiwan

Section10Methods/PracticeProblems/src/FunctionsCC4.java

@@ -1,15 +1,13 @@
-//Storing the returned value in a variable.
-public class FunctionsCC4
-{
-    public static int calculateSum(int num1, int num2)
-    {
+public class FunctionsCC4 {
+    public static int calculateSum(int num1, int num2) {
         return num1 + num2;
     }
-    public static void main(String[] args)
-    {
+    public static void main(String[] args) {
+        //Storing the returned value in a variable.
         int sum = 0;
         sum = calculateSum(3, 4);
+        //calling a calculate sum method,
         int avg = sum / 2;
         System.out.println(avg);
     }
-}
+}