diff --git a/app/src/main/java/htw/berlin/prog2/ha1/Calculator.java b/app/src/main/java/htw/berlin/prog2/ha1/Calculator.java
index 84c04f2..dd88834 100644
--- a/app/src/main/java/htw/berlin/prog2/ha1/Calculator.java
+++ b/app/src/main/java/htw/berlin/prog2/ha1/Calculator.java
@@ -45,9 +45,14 @@ public void pressDigitKey(int digit) {
      * im Ursprungszustand ist.
      */
     public void pressClearKey() {
-        screen = "0";
-        latestOperation = "";
-        latestValue = 0.0;
+        
+        if (!screen.equals ("0") && latestValue != 0){
+            screen = "0";
+        } else {
+            screen = "0";
+            latestOperation = "";
+            latestValue = 0.0;
+        }
     }
 
     /**
@@ -60,6 +65,9 @@ public void pressClearKey() {
      * @param operation "+" für Addition, "-" für Substraktion, "x" für Multiplikation, "/" für Division
      */
     public void pressBinaryOperationKey(String operation)  {
+        if (!latestOperation.equals("")){
+            pressEqualsKey();
+        }
         latestValue = Double.parseDouble(screen);
         latestOperation = operation;
     }
diff --git a/app/src/test/java/htw/berlin/prog2/ha1/CalculatorTest.java b/app/src/test/java/htw/berlin/prog2/ha1/CalculatorTest.java
index ddff0da..4b8bf54 100644
--- a/app/src/test/java/htw/berlin/prog2/ha1/CalculatorTest.java
+++ b/app/src/test/java/htw/berlin/prog2/ha1/CalculatorTest.java
@@ -90,5 +90,49 @@ void testMultipleDecimalDots() {
 
 
     //TODO hier weitere Tests erstellen
+    @Test
+    @DisplayName("should repeat last operation if equals key is pressed again")
+    void testClearkey() {
+        Calculator calc = new Calculator();
+
+        calc.pressDigitKey(1);
+        calc.pressBinaryOperationKey("+");
+        calc.pressDigitKey(1);
+        calc.pressEqualsKey();
+        assertEquals("2", calc.readScreen());
+        calc.pressEqualsKey();
+        assertEquals("3", calc.readScreen());
+    }
+    
+    @Test
+    @DisplayName("should clear the screen after pressing the clear key")
+    void testClearKey() {
+        Calculator calc = new Calculator();
+        calc.pressDigitKey(5);
+        calc.pressBinaryOperationKey("+");
+        calc.pressDigitKey(6);
+        calc.pressClearKey();
+        calc.pressBinaryOperationKey("+");
+        calc.pressDigitKey(7);
+        calc.pressEqualsKey();
+        String expected = "12";
+        String actual = calc.readScreen();
+
+        assertEquals(expected, actual);
+    }
+
+    @Test
+    @DisplayName("Should display the intermediate result when an operation is performed multiple times.")
+    void testIntermediateResult() {
+        Calculator calc = new Calculator();
+        calc.pressDigitKey(5);
+        calc.pressBinaryOperationKey("+");
+        calc.pressDigitKey(5);
+        calc.pressBinaryOperationKey("+");
+        String expected = "10";
+        String actual = calc.readScreen();
+
+        assertEquals(expected, actual);
+    }
 }