diff --git a/Lab2/Excecise_12_Perfect_Num_First100000.java b/Lab2/Excecise_12_Perfect_Num_First100000.java
new file mode 100644
index 0000000..88742a9
--- /dev/null
+++ b/Lab2/Excecise_12_Perfect_Num_First100000.java
@@ -0,0 +1,15 @@
+package Lab2;
+
+public class Excecise_12_Perfect_Num_First100000 {
+    public static void main(String[] args) {
+        for (int i = 1; i <= 100000; i++) {
+            int sum = 0;
+            for (int j = 1; j <= i / 2; j++) {
+                if (i % j == 0) sum += j;
+            }
+            if (sum == i) {
+                System.out.println(i + " is a Perfect Number.");
+            }
+        }
+    }
+}
diff --git a/Lab2/Exercise_1_FahrenheitToCelsius.java b/Lab2/Exercise_01_FahrenheitToCelsius.java
similarity index 87%
rename from Lab2/Exercise_1_FahrenheitToCelsius.java
rename to Lab2/Exercise_01_FahrenheitToCelsius.java
index 3fec90e..40e6539 100644
--- a/Lab2/Exercise_1_FahrenheitToCelsius.java
+++ b/Lab2/Exercise_01_FahrenheitToCelsius.java
@@ -2,7 +2,7 @@
 
 import java.util.Scanner;
 
-public class Exercise_1_FahrenheitToCelsius {
+public class Exercise_01_FahrenheitToCelsius {
     public static void main(String[] args) {
         Scanner input = new Scanner(System.in);
         System.out.print("Enter Fahrenheit: ");
diff --git a/Lab2/Exercise_2_CylinderVolume.java b/Lab2/Exercise_02_CylinderVolume.java
similarity index 92%
rename from Lab2/Exercise_2_CylinderVolume.java
rename to Lab2/Exercise_02_CylinderVolume.java
index 00f024b..3c81394 100644
--- a/Lab2/Exercise_2_CylinderVolume.java
+++ b/Lab2/Exercise_02_CylinderVolume.java
@@ -2,7 +2,7 @@
 
 import java.util.Scanner;
 
-public class Exercise_2_CylinderVolume {
+public class Exercise_02_CylinderVolume {
     public static void main(String[] args) {
         Scanner input = new Scanner(System.in);
         System.out.print("Enter the radius: ");
diff --git a/Lab2/Exercise_3_SumOfDigits.java b/Lab2/Exercise_03_SumOfDigits.java
similarity index 91%
rename from Lab2/Exercise_3_SumOfDigits.java
rename to Lab2/Exercise_03_SumOfDigits.java
index a335734..2ffe47a 100644
--- a/Lab2/Exercise_3_SumOfDigits.java
+++ b/Lab2/Exercise_03_SumOfDigits.java
@@ -2,7 +2,7 @@
 
 import java.util.Scanner;
 
-public class Exercise_3_SumOfDigits {
+public class Exercise_03_SumOfDigits {
     public static void main(String[] args) {
         Scanner input = new Scanner(System.in);
         System.out.print("Enter a number between 0 and 1000: ");
diff --git a/Lab2/Exercise_04_Uppercase_Letter_to_Lowercase.java b/Lab2/Exercise_04_Uppercase_Letter_to_Lowercase.java
new file mode 100644
index 0000000..4098188
--- /dev/null
+++ b/Lab2/Exercise_04_Uppercase_Letter_to_Lowercase.java
@@ -0,0 +1,13 @@
+package Lab2;
+
+import java.util.Scanner;
+
+public class Exercise_04_Uppercase_Letter_to_Lowercase {
+    public static void main(String[] args) {
+        Scanner input = new Scanner(System.in);
+        System.out.print("Enter an uppercase letter: ");
+        char upper = input.next().charAt(0);
+        char lower = Character.toLowerCase(upper);
+        System.out.println("Lowercase letter: " + lower);
+    }
+}
\ No newline at end of file
diff --git a/Lab2/Exercise_05_Character_to_ASCII.java b/Lab2/Exercise_05_Character_to_ASCII.java
new file mode 100644
index 0000000..7b7b8c8
--- /dev/null
+++ b/Lab2/Exercise_05_Character_to_ASCII.java
@@ -0,0 +1,13 @@
+package Lab2;
+
+import java.util.Scanner;
+
+public class Exercise_05_Character_to_ASCII {
+    public static void main(String[] args) {
+        Scanner input = new Scanner(System.in);
+        System.out.print("Enter an ASCII code (0 to 128): ");
+        int ascii = input.nextInt();
+        char character = (char) ascii;
+        System.out.println("Character: " + character);
+    }
+}
diff --git a/Lab2/Exercise_06_Max_Day_in_Month.java b/Lab2/Exercise_06_Max_Day_in_Month.java
new file mode 100644
index 0000000..13d7ee9
--- /dev/null
+++ b/Lab2/Exercise_06_Max_Day_in_Month.java
@@ -0,0 +1,33 @@
+package Lab2;
+
+import java.util.Scanner;
+
+public class Exercise_06_Max_Day_in_Month {
+    public static void main(String[] args) {
+        Scanner input = new Scanner(System.in);
+        System.out.print("Enter month (1-12): ");
+        int month = input.nextInt();
+        System.out.print("Enter year: ");
+        int year = input.nextInt();
+        
+        int days;
+        switch (month) {
+            case 1: case 3: case 5: case 7: case 8: case 10: case 12:
+                days = 31;
+                break;
+            case 4: case 6: case 9: case 11:
+                days = 30;
+                break;
+            case 2:
+                if ((year % 4 == 0 && year % 100 != 0) || (year % 400 == 0)) {
+                    days = 29;
+                } else {
+                    days = 28;
+                }
+                break;
+            default:
+                days = 0; // Invalid month
+        }
+        System.out.println("Days in month: " + days);
+    }
+}
diff --git a/Lab2/Exercise_07_Grade_Marks.java b/Lab2/Exercise_07_Grade_Marks.java
new file mode 100644
index 0000000..d95a20d
--- /dev/null
+++ b/Lab2/Exercise_07_Grade_Marks.java
@@ -0,0 +1,23 @@
+package Lab2;
+
+import java.util.Scanner;
+
+public class Exercise_07_Grade_Marks {
+    public static void main(String[] args) {
+        Scanner input = new Scanner(System.in);
+        System.out.print("Enter your assignment marks: ");
+        int marks = input.nextInt();
+        String grade;
+        
+        if (marks >= 0 && marks <= 40) grade = "F (Fail)";
+        else if (marks <= 49) grade = "F+ (Marginal Fail)";
+        else if (marks <= 54) grade = "D (Pass)";
+        else if (marks <= 64) grade = "C";
+        else if (marks <= 69) grade = "B (Credit)";
+        else if (marks <= 74) grade = "B+";
+        else if (marks <= 79) grade = "A (Distinction)";
+        else grade = "A+";
+        
+        System.out.println("Grade: " + grade);
+    }
+}
diff --git a/Lab2/Exercise_08_Sum_in_Double_Array.java b/Lab2/Exercise_08_Sum_in_Double_Array.java
new file mode 100644
index 0000000..6338369
--- /dev/null
+++ b/Lab2/Exercise_08_Sum_in_Double_Array.java
@@ -0,0 +1,20 @@
+package Lab2;
+
+public class Exercise_08_Sum_in_Double_Array {
+    public static void main(String[] args) {
+        double[] numbers = new double[100];
+        double sum = 0;
+        
+        // Initialize array with some values
+        for (int i = 0; i < numbers.length; i++) {
+            numbers[i] = i + 1; // Fill with values 1 to 100
+        }
+        
+        // Enhanced for loop
+        for (double num : numbers) {
+            sum += num;
+        }
+        
+        System.out.println("Sum of all values: " + sum);
+    }
+}
\ No newline at end of file
diff --git a/Lab2/Exercise_09_Compute_University_Tuition.java b/Lab2/Exercise_09_Compute_University_Tuition.java
new file mode 100644
index 0000000..2550cb4
--- /dev/null
+++ b/Lab2/Exercise_09_Compute_University_Tuition.java
@@ -0,0 +1,14 @@
+package Lab2;
+
+public class Exercise_09_Compute_University_Tuition {
+    public static void main(String[] args) {
+        double tuition = 10000;
+        double rate = 0.05;
+        
+        for (int year = 1; year <= 10; year++) {
+            tuition += tuition * rate;
+        }
+        
+        System.out.println("Tuition after 10 years: RM" + tuition);
+    }
+}
diff --git a/Lab2/Exercise_10_Program_execution.java b/Lab2/Exercise_10_Program_execution.java
new file mode 100644
index 0000000..54c8ecb
--- /dev/null
+++ b/Lab2/Exercise_10_Program_execution.java
@@ -0,0 +1,19 @@
+package Lab2;
+
+import java.util.Scanner;
+
+public class Exercise_10_Program_execution {
+
+        public static void main(String[] args) {
+        Scanner input = new Scanner(System.in);
+        String choice;
+        
+        do {
+            System.out.println("Program is running...");
+            System.out.print("Do you want to continue (Yes/No)? ");
+            choice = input.next();
+        } while (choice.equalsIgnoreCase("Yes"));
+        
+        System.out.println("Program terminated.");
+    }
+}
\ No newline at end of file
diff --git a/Lab2/Exercise_11_Investment_Value_Calculation.java b/Lab2/Exercise_11_Investment_Value_Calculation.java
new file mode 100644
index 0000000..8677c50
--- /dev/null
+++ b/Lab2/Exercise_11_Investment_Value_Calculation.java
@@ -0,0 +1,18 @@
+package Lab2;
+
+import java.util.Scanner;
+
+public class Exercise_11_Investment_Value_Calculation {
+        public static void main(String[] args) {
+        Scanner input = new Scanner(System.in);
+        System.out.print("Enter investment amount: ");
+        double investmentAmount = input.nextDouble();
+        System.out.print("Enter annual interest rate (in percentage): ");
+        double annualInterestRate = input.nextDouble();
+        System.out.print("Enter number of years: ");
+        int years = input.nextInt();
+        
+        double futureInvestmentValue = investmentAmount * Math.pow((1 + annualInterestRate / 100), years);
+        System.out.println("Future investment value: " + futureInvestmentValue);
+    }
+}
diff --git a/Lab2/Exercise_13_Sum_of_Prime_Num_First100.java b/Lab2/Exercise_13_Sum_of_Prime_Num_First100.java
new file mode 100644
index 0000000..b3545c8
--- /dev/null
+++ b/Lab2/Exercise_13_Sum_of_Prime_Num_First100.java
@@ -0,0 +1,21 @@
+package Lab2;
+
+public class Exercise_13_Sum_of_Prime_Num_First100 {
+    public static void main(String[] args) {
+        int sum = 0;
+        for (int i = 2; i < 100; i++) {
+            if (isPrime(i)) {
+                sum += i;
+            }
+        }
+        System.out.println("Sum of prime numbers in the first 100 numbers: " + sum);
+    }
+
+    public static boolean isPrime(int n) {
+        if (n <= 1) return false;
+        for (int i = 2; i <= Math.sqrt(n); i++) {
+            if (n % i == 0) return false;
+        }
+        return true;
+    }
+}