diff --git a/src/de/dhbwka/java/exercise/classes/Complex.java b/src/de/dhbwka/java/exercise/classes/Complex.java
new file mode 100644
index 0000000..a67658a
--- /dev/null
+++ b/src/de/dhbwka/java/exercise/classes/Complex.java
@@ -0,0 +1,53 @@
+package de.dhbwka.java.exercise.classes;
+
+public class Complex {
+  private double real;
+  private double imag;
+
+  public Complex(double real, double imag) {
+    this.real = real;
+    this.imag = imag;
+  }
+
+  public Complex() {
+    this(0, 0);
+  }
+
+  public double getMagnitude() {
+    return Math.sqrt(real * real + imag * imag);
+  }
+
+  public boolean isLessThan(Complex c) {
+    return this.getMagnitude() < c.getMagnitude();
+  }
+
+  public Complex add(Complex c) {
+    return new Complex(this.real + c.real, this.imag + c.imag);
+  }
+
+  public Complex sub(Complex c) {
+    return new Complex(this.real - c.real, this.imag - c.imag);
+  }
+
+  public Complex mul(Complex c) {
+    return new Complex(this.real * c.real - this.imag * c.imag, this.real * c.imag + this.imag * c.real);
+  }
+
+  public Complex div(Complex c) {
+    return new Complex((this.real * c.real + this.imag * c.imag) / (c.real * c.real + c.imag * c.imag),
+        (this.imag * c.real - this.real * c.imag) / (c.real * c.real + c.imag * c.imag));
+  }
+
+  public double getImag() {
+    return imag;
+  }
+
+  public double getReal() {
+    return real;
+  }
+
+  @Override
+  public String toString() {
+    return real + (imag >= 0 ? "+" : "") + imag + "i";
+  }
+}
diff --git a/src/de/dhbwka/java/exercise/classes/ComplexTest.java b/src/de/dhbwka/java/exercise/classes/ComplexTest.java
new file mode 100644
index 0000000..d3afc46
--- /dev/null
+++ b/src/de/dhbwka/java/exercise/classes/ComplexTest.java
@@ -0,0 +1,26 @@
+package de.dhbwka.java.exercise.classes;
+
+public class ComplexTest {
+  public static void main(String[] args) {
+    Complex[] complexNumbers = new Complex[10];
+
+    for (int i = 0; i < complexNumbers.length; i++) {
+      complexNumbers[i] = new Complex(Math.floor(Math.random() * 10), Math.floor(Math.random() * 10));
+    }
+
+    // Bubble sort
+    for (int i = 0; i < complexNumbers.length; i++) {
+      for (int j = 0; j < complexNumbers.length - 1; j++) {
+        if (complexNumbers[j].isLessThan(complexNumbers[j + 1])) {
+          Complex temp = complexNumbers[j];
+          complexNumbers[j] = complexNumbers[j + 1];
+          complexNumbers[j + 1] = temp;
+        }
+      }
+    }
+
+    for (Complex complex : complexNumbers) {
+      System.out.println(complex);
+    }
+  }
+}
diff --git a/src/de/dhbwka/java/exercise/classes/Horner.java b/src/de/dhbwka/java/exercise/classes/Horner.java
new file mode 100644
index 0000000..27cd0b1
--- /dev/null
+++ b/src/de/dhbwka/java/exercise/classes/Horner.java
@@ -0,0 +1,37 @@
+package de.dhbwka.java.exercise.classes;
+
+public class Horner {
+  private double[] coefficients;
+
+  public Horner(double[] coefficients) {
+    this.coefficients = coefficients;
+  }
+
+  public double getValue(double x) {
+    double result = 0;
+
+    for (int i = coefficients.length - 1; i >= 0; i--) {
+      result = coefficients[i] + x * result;
+    }
+
+    return result;
+  }
+
+  @Override
+  public String toString() {
+    StringBuilder sb = new StringBuilder();
+
+    for (int i = 0; i < coefficients.length; i++) {
+      sb.append(coefficients[i]);
+
+      if (i > 0) {
+        sb.append("x^").append(i);
+      }
+      if (i < coefficients.length - 1) {
+        sb.append(" + ");
+      }
+    }
+
+    return sb.toString();
+  }
+}
diff --git a/src/de/dhbwka/java/exercise/classes/HornerTest.java b/src/de/dhbwka/java/exercise/classes/HornerTest.java
new file mode 100644
index 0000000..413d24e
--- /dev/null
+++ b/src/de/dhbwka/java/exercise/classes/HornerTest.java
@@ -0,0 +1,11 @@
+package de.dhbwka.java.exercise.classes;
+
+public class HornerTest {
+  public static void main(String[] args) {
+    Horner h = new Horner(new double[] { 1, 2, 3, 4, 5 });
+    System.out.println(h.getValue(2));
+    System.out.println(h.getValue(3));
+
+    System.out.println(h);
+  }
+}
diff --git a/src/de/dhbwka/java/exercise/classes/Lotto.java b/src/de/dhbwka/java/exercise/classes/Lotto.java
new file mode 100644
index 0000000..d35ba4e
--- /dev/null
+++ b/src/de/dhbwka/java/exercise/classes/Lotto.java
@@ -0,0 +1,81 @@
+package de.dhbwka.java.exercise.classes;
+
+import java.util.Arrays;
+import java.util.Random;
+import java.util.Scanner;
+
+public class Lotto {
+  private int m;
+  private int n;
+  private int[] tipp;
+  private int[] gezogeneZahlen;
+  private Random random = new Random();
+
+  public Lotto(int m, int n) {
+    this.m = m;
+    this.n = n;
+    this.tipp = new int[m];
+    this.gezogeneZahlen = new int[m];
+  }
+
+  public void tippen() {
+    Scanner scanner = new Scanner(System.in);
+    for (int i = 0; i < m; i++) {
+      System.out.printf("Geben Sie bitte Ihren Tipp für die %d. Zahl ein: ", i + 1);
+      tipp[i] = scanner.nextInt();
+      while (tipp[i] < 1 || tipp[i] > n) {
+        System.out.printf("Ungültige Zahl. Geben Sie bitte Ihren Tipp für die %d. Zahl ein: ", i + 1);
+        tipp[i] = scanner.nextInt();
+      }
+    }
+    Arrays.sort(tipp);
+    scanner.close();
+  }
+
+  public void tippen(int[] tipp) {
+    if (tipp.length != m) {
+      throw new IllegalArgumentException("Die Länge des Tipps muss " + m + " sein.");
+    }
+    this.tipp = Arrays.copyOf(tipp, tipp.length);
+    Arrays.sort(this.tipp);
+  }
+
+  public void ziehen() {
+    for (int i = 0; i < m; i++) {
+      int zahl;
+      do {
+        zahl = random.nextInt(n) + 1;
+      } while (contains(gezogeneZahlen, zahl));
+      gezogeneZahlen[i] = zahl;
+    }
+    Arrays.sort(gezogeneZahlen);
+  }
+
+  public int richtige() {
+    int count = 0;
+    for (int zahl : tipp) {
+      if (contains(gezogeneZahlen, zahl)) {
+        count++;
+      }
+    }
+    return count;
+  }
+
+  private boolean contains(int[] array, int value) {
+    for (int i : array) {
+      if (i == value) {
+        return true;
+      }
+    }
+    return false;
+  }
+
+  @Override
+  public String toString() {
+    StringBuilder sb = new StringBuilder();
+    sb.append("Tipp: ").append(Arrays.toString(tipp)).append("\n");
+    sb.append("Gezogene Zahlen: ").append(Arrays.toString(gezogeneZahlen)).append("\n");
+    sb.append("Richtige: ").append(richtige());
+    return sb.toString();
+  }
+}
diff --git a/src/de/dhbwka/java/exercise/classes/LottoTest.java b/src/de/dhbwka/java/exercise/classes/LottoTest.java
new file mode 100644
index 0000000..fd0a887
--- /dev/null
+++ b/src/de/dhbwka/java/exercise/classes/LottoTest.java
@@ -0,0 +1,10 @@
+package de.dhbwka.java.exercise.classes;
+
+public class LottoTest {
+  public static void main(String[] args) {
+    Lotto deutschesLotto = new Lotto(6, 49);
+    deutschesLotto.tippen(new int[] { 1, 11, 17, 22, 33, 49 });
+    deutschesLotto.ziehen();
+    System.out.println(deutschesLotto);
+  }
+}
diff --git a/src/de/dhbwka/java/exercise/classes/MasterMind.java b/src/de/dhbwka/java/exercise/classes/MasterMind.java
new file mode 100644
index 0000000..82a70d9
--- /dev/null
+++ b/src/de/dhbwka/java/exercise/classes/MasterMind.java
@@ -0,0 +1,90 @@
+package de.dhbwka.java.exercise.classes;
+
+import java.util.Random;
+import java.util.Scanner;
+
+public class MasterMind {
+  private static final int COMBINATION_LENGTH = 5;
+  private static final int MAX_ATTEMPTS = 20;
+  private static final char[] COLORS = { 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H' };
+  private String secretCombination;
+
+  public MasterMind() {
+    this.secretCombination = generateSecretCombination();
+  }
+
+  private String generateSecretCombination() {
+    Random random = new Random();
+    StringBuilder combination = new StringBuilder(COMBINATION_LENGTH);
+    for (int i = 0; i < COMBINATION_LENGTH; i++) {
+      combination.append(COLORS[random.nextInt(COLORS.length)]);
+    }
+    return combination.toString();
+  }
+
+  public void play() {
+    Scanner scanner = new Scanner(System.in);
+    int attempts = 0;
+    boolean won = false;
+
+    System.out.println("Welcome to MasterMind!");
+    System.out.println("Try to guess the combination of 5 letters (A to H). You have " + MAX_ATTEMPTS + " attempts.");
+
+    while (attempts < MAX_ATTEMPTS && !won) {
+      System.out.print("Enter your guess: ");
+      String guess = scanner.nextLine().toUpperCase();
+
+      if (guess.length() != COMBINATION_LENGTH) {
+        System.out.println("Invalid input. Please enter exactly " + COMBINATION_LENGTH + " letters.");
+        continue;
+      }
+
+      attempts++;
+      int[] result = evaluateGuess(guess);
+      System.out.println("Correct positions: " + result[0] + ", Correct letters in wrong positions: " + result[1]);
+
+      if (result[0] == COMBINATION_LENGTH) {
+        won = true;
+        System.out.println("Congratulations! You've guessed the correct combination.");
+      }
+    }
+
+    if (!won) {
+      System.out.println("Sorry, you've used all your attempts. The correct combination was: " + secretCombination);
+    }
+
+    scanner.close();
+  }
+
+  private int[] evaluateGuess(String guess) {
+    int correctPositions = 0;
+    int correctLettersWrongPositions = 0;
+    boolean[] secretUsed = new boolean[COMBINATION_LENGTH];
+    boolean[] guessUsed = new boolean[COMBINATION_LENGTH];
+
+    // First pass: check for correct positions
+    for (int i = 0; i < COMBINATION_LENGTH; i++) {
+      if (guess.charAt(i) == secretCombination.charAt(i)) {
+        correctPositions++;
+        secretUsed[i] = true;
+        guessUsed[i] = true;
+      }
+    }
+
+    // Second pass: check for correct letters in wrong positions
+    for (int i = 0; i < COMBINATION_LENGTH; i++) {
+      if (!guessUsed[i]) {
+        for (int j = 0; j < COMBINATION_LENGTH; j++) {
+          if (!secretUsed[j] && guess.charAt(i) == secretCombination.charAt(j)) {
+            correctLettersWrongPositions++;
+            secretUsed[j] = true;
+            break;
+          }
+        }
+      }
+    }
+
+    return new int[] { correctPositions, correctLettersWrongPositions };
+  }
+
+}
diff --git a/src/de/dhbwka/java/exercise/classes/MasterMindTest.java b/src/de/dhbwka/java/exercise/classes/MasterMindTest.java
new file mode 100644
index 0000000..0440684
--- /dev/null
+++ b/src/de/dhbwka/java/exercise/classes/MasterMindTest.java
@@ -0,0 +1,8 @@
+package de.dhbwka.java.exercise.classes;
+
+public record MasterMindTest() {
+  public static void main(String[] args) {
+    MasterMind game = new MasterMind();
+    game.play();
+  }
+}
diff --git a/src/de/dhbwka/java/exercise/classes/Nimmspiel.java b/src/de/dhbwka/java/exercise/classes/Nimmspiel.java
new file mode 100644
index 0000000..43134ed
--- /dev/null
+++ b/src/de/dhbwka/java/exercise/classes/Nimmspiel.java
@@ -0,0 +1,58 @@
+package de.dhbwka.java.exercise.classes;
+
+import java.util.Scanner;
+
+public class Nimmspiel {
+  private String player1;
+  private String player2;
+  private int heap1;
+  private int heap2;
+  private boolean isPlayer1Turn;
+
+  public Nimmspiel(String player1, String player2) {
+    this.player1 = player1;
+    this.player2 = player2;
+    this.heap1 = (int) (Math.random() * 10) + 1;
+    this.heap2 = (int) (Math.random() * 10) + 1;
+    this.isPlayer1Turn = true;
+  }
+
+  public String toString() {
+    return "Spieler: " + player1 + " und " + player2 + ", Haufen 1: " + heap1 + " Kugel(n), Haufen 2: " + heap2
+        + " Kugel(n)";
+  }
+
+  public boolean isGameOver() {
+    return heap1 == 0 && heap2 == 0;
+  }
+
+  public void makeMove(int heap, int balls) {
+    if (heap == 1) {
+      heap1 -= balls;
+    } else {
+      heap2 -= balls;
+    }
+    isPlayer1Turn = !isPlayer1Turn;
+  }
+
+  public void play() {
+    Scanner scanner = new Scanner(System.in);
+    while (!isGameOver()) {
+      System.out.println(this);
+      String currentPlayer = isPlayer1Turn ? player1 : player2;
+      System.out.println("Spieler " + currentPlayer + ": Von welchem Haufen ziehen Sie Kugeln? (1 oder 2)");
+      int heap = scanner.nextInt();
+      System.out.println("Spieler " + currentPlayer + ": Wieviele Kugeln ziehen Sie?");
+      int balls = scanner.nextInt();
+      if ((heap == 1 && balls > 0 && balls <= heap1) || (heap == 2 && balls > 0 && balls <= heap2)) {
+        makeMove(heap, balls);
+      } else {
+        System.out.println("Ungültiger Zug, bitte erneut versuchen.");
+      }
+    }
+    scanner.close();
+    System.out.println("Spiel beendet.");
+    String winner = isPlayer1Turn ? player2 : player1;
+    System.out.println("Gewonnen hat Spieler " + winner);
+  }
+}
diff --git a/src/de/dhbwka/java/exercise/classes/NimmspielTest.java b/src/de/dhbwka/java/exercise/classes/NimmspielTest.java
new file mode 100644
index 0000000..f93209f
--- /dev/null
+++ b/src/de/dhbwka/java/exercise/classes/NimmspielTest.java
@@ -0,0 +1,16 @@
+package de.dhbwka.java.exercise.classes;
+
+import java.util.Scanner;
+
+public class NimmspielTest {
+  public static void main(String[] args) {
+    Scanner scanner = new Scanner(System.in);
+    System.out.println("Bitte geben Sie den Namen des ersten Spielers ein:");
+    String player1 = scanner.nextLine();
+    System.out.println("Bitte geben Sie den Namen des zweiten Spielers ein:");
+    String player2 = scanner.nextLine();
+    Nimmspiel game = new Nimmspiel(player1, player2);
+    game.play();
+    scanner.close();
+  }
+}
diff --git a/src/de/dhbwka/java/exercise/classes/Polynomial.java b/src/de/dhbwka/java/exercise/classes/Polynomial.java
new file mode 100644
index 0000000..ee86499
--- /dev/null
+++ b/src/de/dhbwka/java/exercise/classes/Polynomial.java
@@ -0,0 +1,93 @@
+package de.dhbwka.java.exercise.classes;
+
+public class Polynomial {
+  private double[] factors;
+
+  public Polynomial(double[] factors) {
+    if (factors == null || factors.length != 3) {
+      throw new IllegalArgumentException("Factors must not be null and must have a length of 3");
+    }
+    this.factors = factors;
+  }
+
+  public double[] getFactors() {
+    return factors;
+  }
+
+  public void setFactors(double[] factors) {
+    this.factors = factors;
+  }
+
+  @Override
+  public String toString() {
+    String result = "";
+
+    if (factors[0] != 0) {
+      if (factors[0] < 0) {
+        result += "-";
+      }
+      if (factors[0] != 1 && factors[0] != -1) {
+        result += Math.abs(factors[0]);
+      }
+      result += "x^2";
+    }
+
+    if (factors[1] != 0) {
+      if (factors[1] < 0) {
+        result += " - ";
+      } else if (factors[0] != 0) {
+        result += " + ";
+      }
+      if (factors[1] != 1 && factors[1] != -1) {
+        result += Math.abs(factors[1]);
+      }
+      result += "x";
+    }
+
+    if (factors[2] != 0) {
+      if (factors[2] < 0) {
+        result += " - ";
+      } else if (factors[0] != 0 || factors[1] != 0) {
+        result += " + ";
+      }
+      result += Math.abs(factors[2]);
+    }
+
+    return result;
+  }
+
+  public double evaluate(double x) {
+    return factors[0] * x * x + factors[1] * x + factors[2];
+  }
+
+  public Polynomial add(Polynomial p) {
+    return new Polynomial(
+        new double[] { factors[0] + p.factors[0], factors[1] + p.factors[1], factors[2] + p.factors[2] });
+  }
+
+  public Polynomial sub(Polynomial p) {
+    return new Polynomial(
+        new double[] { factors[0] - p.factors[0], factors[1] - p.factors[1], factors[2] - p.factors[2] });
+  }
+
+  public Polynomial scalarMul(double scalar) {
+    return new Polynomial(new double[] { factors[0] * scalar, factors[1] * scalar, factors[2] * scalar });
+  }
+
+  public double[] findRoots() {
+    double discriminant = factors[1] * factors[1] - 4 * factors[0] * factors[2];
+    if (factors[0] == 0 && factors[1] == 0) {
+      return new double[0];
+    } else if (factors[0] == 0) {
+      return new double[] { -factors[2] / factors[1] };
+    } else if (discriminant < 0) {
+      return new double[0];
+    } else if (discriminant == 0) {
+      return new double[] { -factors[1] / (2 * factors[0]) };
+    } else {
+      double root1 = (-factors[1] + Math.sqrt(discriminant)) / (2 * factors[0]);
+      double root2 = (-factors[1] - Math.sqrt(discriminant)) / (2 * factors[0]);
+      return new double[] { root1, root2 };
+    }
+  }
+}
diff --git a/src/de/dhbwka/java/exercise/classes/PolynomialTest.java b/src/de/dhbwka/java/exercise/classes/PolynomialTest.java
new file mode 100644
index 0000000..06e4235
--- /dev/null
+++ b/src/de/dhbwka/java/exercise/classes/PolynomialTest.java
@@ -0,0 +1,24 @@
+package de.dhbwka.java.exercise.classes;
+
+public class PolynomialTest {
+  public static void main(String[] args) {
+    Polynomial p1 = new Polynomial(new double[] { 1, 2, 3 });
+    Polynomial p2 = new Polynomial(new double[] { 0, -3, 4 });
+
+    Polynomial p3 = p1.add(p2);
+
+    System.out.println(p1 + " + " + p2 + " = " + p3);
+
+    Polynomial p4 = p1.scalarMul(2);
+
+    System.out.println(p1 + " * 2 = " + p4);
+
+    System.out.println(p1 + " evaluated at x=2: " + p1.evaluate(2));
+    System.out.println(p2 + " evaluated at x=2: " + p2.evaluate(2));
+    System.out.println(p3 + " evaluated at x=2: " + p3.evaluate(2));
+    System.out.println(p4 + " evaluated at x=2: " + p4.evaluate(2));
+
+    double[] roots = p2.findRoots();
+    System.out.println("Root: " + roots[0]);
+  }
+}