diff --git a/NumberGuessingGame.java b/NumberGuessingGame.java
new file mode 100644
index 0000000..f952baa
--- /dev/null
+++ b/NumberGuessingGame.java
@@ -0,0 +1,47 @@
+import java.util.Random;
+import java.util.Scanner;
+
+public class NumberGuessingGame {
+    public static void main(String[] args) {
+        // Create a Random object to generate random numbers
+        Random random = new Random();
+        
+        // Generate a random number between 1 and 100
+        int targetNumber = random.nextInt(100) + 1;
+        
+        // Maximum number of attempts
+        int maxAttempts = 10;
+        
+        // Create a Scanner object for user input
+        Scanner scanner = new Scanner(System.in);
+        
+        System.out.println("Welcome to the Number Guessing Game!");
+        System.out.println("I have generated a random number between 1 and 100.");
+        System.out.println("You have " + maxAttempts + " attempts to guess it.");
+        
+        // Variable to track the number of attempts used
+        int attempts = 0;
+        
+        while (attempts < maxAttempts) {
+            System.out.print("Enter your guess: ");
+            int guess = scanner.nextInt();
+            attempts++;
+            
+            if (guess == targetNumber) {
+                System.out.println("Congratulations! You guessed the number in " + attempts + " attempts.");
+                break;
+            } else if (guess < targetNumber) {
+                System.out.println("Too low! Try again.");
+            } else {
+                System.out.println("Too high! Try again.");
+            }
+            
+            if (attempts == maxAttempts) {
+                System.out.println("Sorry, you've used all " + maxAttempts + " attempts. The correct number was " + targetNumber + ".");
+            }
+        }
+        
+        // Close the scanner
+        scanner.close();
+    }
+}
diff --git a/Simple_calci.java b/Simple_calci.java
new file mode 100644
index 0000000..fc497f2
--- /dev/null
+++ b/Simple_calci.java
@@ -0,0 +1,71 @@
+import java.util.Scanner;
+
+public class Simple_calci {
+    public static void main(String[] args) {
+        Scanner scanner = new Scanner(System.in);
+        boolean exit = false;
+        
+        while (!exit) {
+            showMenu();
+            int choice = scanner.nextInt();
+            switch (choice) {
+                case 1:
+                    performOperation(scanner, "add");
+                    break;
+                case 2:
+                    performOperation(scanner, "subtract");
+                    break;
+                case 3:
+                    performOperation(scanner, "multiply");
+                    break;
+                case 4:
+                    performOperation(scanner, "divide");
+                    break;
+                case 5:
+                    exit = true;
+                    System.out.println("Exiting the calculator. Goodbye!");
+                    break;
+                default:
+                    System.out.println("Invalid choice. Please try again.");
+            }
+        }
+        
+        scanner.close();
+    }
+
+    private static void showMenu() {
+        System.out.println("\n--- Basic Calculator ---");
+        System.out.println("1. Addition");
+        System.out.println("2. Subtraction");
+        System.out.println("3. Multiplication");
+        System.out.println("4. Division");
+        System.out.println("5. Exit");
+        System.out.print("Enter your choice: ");
+    }
+
+    private static void performOperation(Scanner scanner, String operation) {
+        System.out.print("Enter the first number: ");
+        double num1 = scanner.nextDouble();
+        System.out.print("Enter the second number: ");
+        double num2 = scanner.nextDouble();
+
+        switch (operation) {
+            case "add":
+                System.out.printf("Result: %.2f + %.2f = %.2f\n", num1, num2, num1 + num2);
+                break;
+            case "subtract":
+                System.out.printf("Result: %.2f - %.2f = %.2f\n", num1, num2, num1 - num2);
+                break;
+            case "multiply":
+                System.out.printf("Result: %.2f * %.2f = %.2f\n", num1, num2, num1 * num2);
+                break;
+            case "divide":
+                if (num2 != 0) {
+                    System.out.printf("Result: %.2f / %.2f = %.2f\n", num1, num2, num1 / num2);
+                } else {
+                    System.out.println("Error: Division by zero is not allowed.");
+                }
+                break;
+        }
+    }
+}
diff --git a/Temp_converter.java b/Temp_converter.java
new file mode 100644
index 0000000..d097426
--- /dev/null
+++ b/Temp_converter.java
@@ -0,0 +1,87 @@
+import java.util.Scanner;
+
+public class Temp_converter {
+
+    // Method to convert Celsius to Fahrenheit
+    public static double celsiusToFahrenheit(double celsius) {
+        return (celsius * 9/5) + 32;
+    }
+
+    // Method to convert Celsius to Kelvin
+    public static double celsiusToKelvin(double celsius) {
+        return celsius + 273.15;
+    }
+
+    // Method to convert Fahrenheit to Celsius
+    public static double fahrenheitToCelsius(double fahrenheit) {
+        return (fahrenheit - 32) * 5/9;
+    }
+
+    // Method to convert Fahrenheit to Kelvin
+    public static double fahrenheitToKelvin(double fahrenheit) {
+        return (fahrenheit - 32) * 5/9 + 273.15;
+    }
+
+    // Method to convert Kelvin to Celsius
+    public static double kelvinToCelsius(double kelvin) {
+        return kelvin - 273.15;
+    }
+
+    // Method to convert Kelvin to Fahrenheit
+    public static double kelvinToFahrenheit(double kelvin) {
+        return (kelvin - 273.15) * 9/5 + 32;
+    }
+
+    public static void main(String[] args) {
+        Scanner scanner = new Scanner(System.in);
+
+        System.out.println("Temperature Converter");
+        System.out.println("=====================");
+        System.out.println("Choose the conversion type:");
+        System.out.println("1. Celsius to Fahrenheit");
+        System.out.println("2. Celsius to Kelvin");
+        System.out.println("3. Fahrenheit to Celsius");
+        System.out.println("4. Fahrenheit to Kelvin");
+        System.out.println("5. Kelvin to Celsius");
+        System.out.println("6. Kelvin to Fahrenheit");
+
+        int choice = scanner.nextInt();
+
+        System.out.print("Enter the temperature value: ");
+        double tempValue = scanner.nextDouble();
+
+        double convertedValue = 0;
+
+        switch (choice) {
+            case 1:
+                convertedValue = celsiusToFahrenheit(tempValue);
+                System.out.println(tempValue + " Celsius is equal to " + convertedValue + " Fahrenheit.");
+                break;
+            case 2:
+                convertedValue = celsiusToKelvin(tempValue);
+                System.out.println(tempValue + " Celsius is equal to " + convertedValue + " Kelvin.");
+                break;
+            case 3:
+                convertedValue = fahrenheitToCelsius(tempValue);
+                System.out.println(tempValue + " Fahrenheit is equal to " + convertedValue + " Celsius.");
+                break;
+            case 4:
+                convertedValue = fahrenheitToKelvin(tempValue);
+                System.out.println(tempValue + " Fahrenheit is equal to " + convertedValue + " Kelvin.");
+                break;
+            case 5:
+                convertedValue = kelvinToCelsius(tempValue);
+                System.out.println(tempValue + " Kelvin is equal to " + convertedValue + " Celsius.");
+                break;
+            case 6:
+                convertedValue = kelvinToFahrenheit(tempValue);
+                System.out.println(tempValue + " Kelvin is equal to " + convertedValue + " Fahrenheit.");
+                break;
+            default:
+                System.out.println("Invalid choice.");
+                break;
+        }
+
+        scanner.close();
+    }
+}
diff --git a/Todo_list.java b/Todo_list.java
new file mode 100644
index 0000000..17b33e2
--- /dev/null
+++ b/Todo_list.java
@@ -0,0 +1,118 @@
+import java.util.ArrayList;
+import java.util.Scanner;
+
+class Task {
+    private String description;
+    private boolean isCompleted;
+
+    public Task(String description) {
+        this.description = description;
+        this.isCompleted = false;
+    }
+
+    public String getDescription() {
+        return description;
+    }
+
+    public boolean isCompleted() {
+        return isCompleted;
+    }
+
+    public void markAsCompleted() {
+        isCompleted = true;
+    }
+
+    @Override
+    public String toString() {
+        return (isCompleted ? "[X] " : "[ ] ") + description;
+    }
+}
+
+public class Todo_list {
+    private static ArrayList<Task> tasks = new ArrayList<>();
+    private static Scanner scanner = new Scanner(System.in);
+
+    public static void main(String[] args) {
+        boolean exit = false;
+        
+        while (!exit) {
+            showMenu();
+            int choice = scanner.nextInt();
+            scanner.nextLine(); // consume newline
+            switch (choice) {
+                case 1:
+                    addTask();
+                    break;
+                case 2:
+                    deleteTask();
+                    break;
+                case 3:
+                    markTaskAsCompleted();
+                    break;
+                case 4:
+                    viewTasks();
+                    break;
+                case 5:
+                    exit = true;
+                    System.out.println("Exiting the task manager. Goodbye!");
+                    break;
+                default:
+                    System.out.println("Invalid choice. Please try again.");
+            }
+        }
+        
+        scanner.close();
+    }
+
+    private static void showMenu() {
+        System.out.println("\n--- Task Manager ---");
+        System.out.println("1. Add Task");
+        System.out.println("2. Delete Task");
+        System.out.println("3. Mark Task as Completed");
+        System.out.println("4. View Tasks");
+        System.out.println("5. Exit");
+        System.out.print("Enter your choice: ");
+    }
+
+    private static void addTask() {
+        System.out.print("Enter the task description: ");
+        String description = scanner.nextLine();
+        tasks.add(new Task(description));
+        System.out.println("Task added successfully.");
+    }
+
+    private static void deleteTask() {
+        System.out.print("Enter the task number to delete: ");
+        int taskNumber = scanner.nextInt();
+        
+        if (taskNumber > 0 && taskNumber <= tasks.size()) {
+            tasks.remove(taskNumber - 1);
+            System.out.println("Task deleted successfully.");
+        } else {
+            System.out.println("Invalid task number. Please try again.");
+        }
+    }
+
+    private static void markTaskAsCompleted() {
+        System.out.print("Enter the task number to mark as completed: ");
+        int taskNumber = scanner.nextInt();
+        
+        if (taskNumber > 0 && taskNumber <= tasks.size()) {
+            tasks.get(taskNumber - 1).markAsCompleted();
+            System.out.println("Task marked as completed.");
+        } else {
+            System.out.println("Invalid task number. Please try again.");
+        }
+    }
+
+    private static void viewTasks() {
+        System.out.println("\n--- Your Tasks ---");
+        if (tasks.isEmpty()) {
+            System.out.println("No tasks available.");
+        } else {
+            for (int i = 0; i < tasks.size(); i++) {
+                System.out.println((i + 1) + ". " + tasks.get(i));
+            }
+        }
+    }
+}