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 addc5f26..31dd1ae6 100644
--- a/app/src/test/java/htw/berlin/prog2/ha1/CalculatorTest.java
+++ b/app/src/test/java/htw/berlin/prog2/ha1/CalculatorTest.java
@@ -3,6 +3,8 @@
 import org.junit.jupiter.api.DisplayName;
 import org.junit.jupiter.api.Test;
 
+import javax.management.loading.MLet;
+
 import static org.junit.jupiter.api.Assertions.assertEquals;
 
 @DisplayName("Retro calculator")
@@ -40,6 +42,75 @@ void testSquareRoot() {
         assertEquals(expected, actual);
     }
 
-    //TODO hier weitere Tests erstellen
+    //1. grüner test
+    @Test
+    @DisplayName("should display result after split two positive multi-digit numbers")
+    void testAddition() {
+        Calculator calc = new Calculator();
+
+        calc.pressDigitKey(1);
+        calc.pressDigitKey(6);
+        calc.pressBinaryOperationKey("/");
+        calc.pressDigitKey(4);
+
+        calc.pressEqualsKey();
+
+        String expected = "4";
+        String actual = calc.readScreen();
+
+        assertEquals(expected, actual);
+    }
+
+    // 1.roter Test
+
+    @Test
+    @DisplayName("should display result after subtract two postive multi-digit-numbers")
+    void testsubtraction() {
+        Calculator calc = new Calculator();
+
+        calc.pressDigitKey(5);
+        calc.pressDigitKey(4);
+        calc.pressBinaryOperationKey("+");
+        calc.pressDigitKey(1);
+        calc.pressDigitKey(8);
+
+        calc.pressEqualsKey();
+
+        String expected = "36";
+        String actual = calc.readScreen();
+
+        assertEquals(expected, actual);
+
+      @@public void pressBinaryOperationKey() {
+
+          if(screen.endWith("+") screen= "-")
+//2.roter test
+      @Test
+      @DisplayName("should display ´0´ result after multiply by zero")
+      void testmultiplication() (
+              Calculator calc= new Calculator()
+            calc.pressDigitKey(2);
+            calc.pressDigitKey(1);
+            calc.pressBinaryOperationKey("*");
+            calc.pressDigitKey(0);
+            calc.pressDigitKey();
+
+            calc.pressEqualsKey();
+
+            String expected = "22";
+            String actual = calc.readScreen();
+
+            assertEquals(expected, actual);
+
+
+                    )
+
+
+
+
+        }
+ @@public void press String expected () {
+
+            if(screen.endWith("22") screen= "0")
 }