diff --git a/projekte/rechner/Rechner.class b/projekte/rechner/Rechner.class
new file mode 100644
index 0000000..2ab5896
Binary files /dev/null and b/projekte/rechner/Rechner.class differ
diff --git a/projekte/rechner/Rechner.java b/projekte/rechner/Rechner.java
new file mode 100644
index 0000000..19870a4
--- /dev/null
+++ b/projekte/rechner/Rechner.java
@@ -0,0 +1,145 @@
+import java.util.Scanner;
+
+public class Rechner {
+
+    public static final double Add = 0;
+    public static final double Sub = 1;
+    public static final double Mul = 2;
+    public static final double Div = 3;
+
+    public static void main(String[] args) {
+        Scanner scan = new Scanner(System.in);
+        System.out.print("Rechnung: ");
+
+        String rechnung = scan.nextLine();
+
+        int numOperands = 0;
+        for (int i = 0; i < rechnung.length(); i++) {
+            char c = rechnung.charAt(i);
+            if (isOperand(c)) {
+                numOperands++;
+            }
+            if (c == '(' && i > 0 && ((rechnung.charAt(i - 1) >= '0' && rechnung.charAt(i - 1) <= '9') || rechnung.charAt(i - 1) == '.' )) {
+                rechnung = rechnung.substring(0, i) + "*" + rechnung.substring(i);
+                i++;
+                numOperands++;
+            }
+            if (c == ')' && i < rechnung.length() - 1 && ((rechnung.charAt(i + 1) >= '0' && rechnung.charAt(i + 1) <= '9') || rechnung.charAt(i + 1) == '.')) {
+                rechnung = rechnung.substring(0, i + 1) + "*" + rechnung.substring(i + 1);
+            }
+        }
+
+        double[] priorities = new double[numOperands];
+        double[] operands = new double[numOperands];
+        double[] terms = new double[numOperands + 1];
+
+        double priority = 0;
+        double highestPriority = 0;
+
+        int operandIndex = 0;
+
+        String currentNum = "";
+        
+        for (int i = 0; i < rechnung.length(); i++) {
+            char c = rechnung.charAt(i);
+
+            if (c == '(') {
+                priority += 2;
+                continue;
+            }
+            if (c == ')') {
+                priority -= 2;
+                continue;
+            }
+
+            if ((c >= '0' && c <= '9') || c == '.') {
+                currentNum = currentNum + c;
+                continue;
+            }
+
+            if (c == '-' && currentNum == "") {
+                currentNum = "-";
+                continue;
+            }
+
+            if (isOperand(c)) {
+                switch (c) {
+                    case '+':
+                        priorities[operandIndex] = priority;
+                        if (priority > highestPriority) {
+                            highestPriority = priority;
+                        }
+                        operands[operandIndex] = Rechner.Add;
+                        break;
+
+                    case '-':
+                        priorities[operandIndex] = priority;
+                        if (priority > highestPriority) {
+                            highestPriority = priority;
+                        }
+                        operands[operandIndex] = Rechner.Sub;
+                        break;
+
+                    case '*':
+                        priorities[operandIndex] = priority + 1;
+                        if (priority + 1> highestPriority) {
+                            highestPriority = priority + 1;
+                        }
+                        operands[operandIndex] = Rechner.Mul;
+                        break;
+
+                    case '/':
+                        priorities[operandIndex] = priority + 1;
+                        if (priority + 1> highestPriority) {
+                            highestPriority = priority + 1;
+                        }
+                        operands[operandIndex] = Rechner.Div;
+                        break;
+                }
+                terms[operandIndex] = Double.parseDouble(currentNum);
+                currentNum = "";
+                operandIndex++;
+            }
+        }
+        terms[operandIndex] = Double.parseDouble(currentNum);
+
+        for (double prio = highestPriority; prio >= 0; prio--) {
+            for (int i = 0; i < operands.length; i++) {
+                if (priorities[i] == prio) {
+                    if (operands[i] == Rechner.Add) {
+                        terms[i + 1] = terms[i] + terms[i + 1];
+                    } else if (operands[i] == Rechner.Sub) {
+                        terms[i + 1] = terms[i] - terms[i + 1];
+                    } else if (operands[i] == Rechner.Mul) {
+                        terms[i + 1] = terms[i] * terms[i + 1];
+                    } else if (operands[i] == Rechner.Div) {
+                        terms[i + 1] = terms[i] / terms[i + 1];
+                    }
+                    terms = removeArrayElement(terms, i);
+                    operands = removeArrayElement(operands, i);
+                    priorities = removeArrayElement(priorities, i);
+                    i--;
+                }
+            }
+        }
+        System.out.println(terms[0]);
+    }
+
+    public static double[] removeArrayElement(double[] arr, int index) {
+        if (index >= arr.length || index < 0) return arr;
+
+        double[] ret = new double[arr.length - 1];
+
+        for (int i = 0; i < arr.length; i++) {
+            if (i == index) continue;
+            
+            ret[i < index ? i : i -1] = arr[i];
+        }
+
+        return ret;
+    }
+
+    public static boolean isOperand(char c) {
+        return c == '+' || c == '-' || c == '*' || c == '/';
+    }
+}
diff --git a/uebungen/h04_1/t01.class b/uebungen/h04_1/t01.class
new file mode 100644
index 0000000..c9892cf
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diff --git a/uebungen/h04_1/t01.java b/uebungen/h04_1/t01.java
new file mode 100644
index 0000000..0661c69
--- /dev/null
+++ b/uebungen/h04_1/t01.java
@@ -0,0 +1,13 @@
+public class t01 {
+    public static void main(String[] args) {
+        for (int i = 1; i <= 5; i++) {
+            for (int j = 1; j <= (5 - i); j++) {
+                System.out.print(" ");
+            }
+            for (int k = 1; k <= i; k++) {
+                System.out.print(i);
+            }
+            System.out.println();
+        }
+    }
+}   
diff --git a/uebungen/h04_figur/Figur.class b/uebungen/h04_figur/Figur.class
new file mode 100644
index 0000000..e1be109
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diff --git a/uebungen/h04_figur/Figur.java b/uebungen/h04_figur/Figur.java
new file mode 100644
index 0000000..b2e62e1
--- /dev/null
+++ b/uebungen/h04_figur/Figur.java
@@ -0,0 +1,39 @@
+public class Figur {
+    public static void main(String[] args) {
+
+
+        zeichneBegrenzer();
+        
+        for (int i = 0; i < 8; i++) {
+            int len = (i >= 4) ? (7 - i) : i;
+
+            System.out.print("|");
+
+            repeatPrintString(" ",6 - len * 2);
+
+            System.out.print("<>");
+
+            repeatPrintString(".", len * 4);
+
+            System.out.print("<>");
+
+            repeatPrintString(" ",6 - len * 2);
+
+            System.out.println("|");
+        }
+
+        zeichneBegrenzer();
+    }
+
+    public static void repeatPrintString(String s, int i) {
+        for (; i > 0; i--) {
+            System.out.print(s);
+        }
+    }
+
+    public static void zeichneBegrenzer() {
+        System.out.print("#");
+        repeatPrintString("=",16);
+        System.out.println("#");
+    }
+}