diff --git a/.idea/gradle.xml b/.idea/gradle.xml
index 440480e..5cd135a 100644
--- a/.idea/gradle.xml
+++ b/.idea/gradle.xml
@@ -1,5 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <project version="4">
+  <component name="GradleMigrationSettings" migrationVersion="1" />
   <component name="GradleSettings">
     <option name="linkedExternalProjectsSettings">
       <GradleProjectSettings>
diff --git a/.idea/misc.xml b/.idea/misc.xml
index 2484353..a291fb3 100644
--- a/.idea/misc.xml
+++ b/.idea/misc.xml
@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <project version="4">
-  <component name="ProjectRootManager" version="2" languageLevel="JDK_15_PREVIEW" default="false" project-jdk-name="15" project-jdk-type="JavaSDK">
+  <component name="ProjectRootManager" version="2" languageLevel="JDK_14" default="false" project-jdk-name="15" project-jdk-type="JavaSDK">
     <output url="file://$PROJECT_DIR$/build/classes" />
   </component>
   <component name="ProjectType">
diff --git a/app/src/main/AndroidManifest.xml b/app/src/main/AndroidManifest.xml
index c75bb1c..a1b06f5 100644
--- a/app/src/main/AndroidManifest.xml
+++ b/app/src/main/AndroidManifest.xml
@@ -9,10 +9,12 @@
         android:roundIcon="@mipmap/ic_launcher_round"
         android:supportsRtl="true"
         android:theme="@style/Theme.Java_mot_testing">
+
+        <activity android:name=".ex9.FractionCalculator"/>
+
         <activity android:name=".MainActivity">
             <intent-filter>
                 <action android:name="android.intent.action.MAIN" />
-
                 <category android:name="android.intent.category.LAUNCHER" />
             </intent-filter>
         </activity>
diff --git a/app/src/main/java/io/n0x/android/java_mot_testing/MainActivity.java b/app/src/main/java/io/n0x/android/java_mot_testing/MainActivity.java
index a25cea0..d3c316c 100644
--- a/app/src/main/java/io/n0x/android/java_mot_testing/MainActivity.java
+++ b/app/src/main/java/io/n0x/android/java_mot_testing/MainActivity.java
@@ -1,14 +1,19 @@
 package io.n0x.android.java_mot_testing;
 
-import androidx.appcompat.app.AppCompatActivity;
+import android.app.Activity;
 
+import android.content.Intent;
 import android.os.Bundle;
 
-public class MainActivity extends AppCompatActivity {
+import io.n0x.android.java_mot_testing.ex9.FractionCalculator;
+
+public class MainActivity extends Activity {
 
     @Override
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
-        setContentView(R.layout.activity_main);
+
+        Intent intent = new Intent(this, FractionCalculator.class);
+        startActivity(intent);
     }
 }
\ No newline at end of file
diff --git a/app/src/main/java/io/n0x/android/java_mot_testing/ex9/FractionCalculator.java b/app/src/main/java/io/n0x/android/java_mot_testing/ex9/FractionCalculator.java
new file mode 100644
index 0000000..53f1d26
--- /dev/null
+++ b/app/src/main/java/io/n0x/android/java_mot_testing/ex9/FractionCalculator.java
@@ -0,0 +1,54 @@
+package io.n0x.android.java_mot_testing.ex9;
+
+import android.app.Activity;
+import android.os.Bundle;
+import android.util.Log;
+import android.view.View;
+import android.widget.TextView;
+
+import io.n0x.android.java_mot_testing.R;
+
+public class FractionCalculator extends Activity{
+
+    private static final String TAG = FractionCalculator.class.getName();
+
+    private TextView txt_enum_left;
+    private TextView txt_denom_left;
+    private TextView txt_enum_right;
+    private TextView txt_denom_right;
+    private TextView txt_enum_result;
+    private TextView txt_denom_result;
+
+    @Override
+    protected void onCreate(Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+        setContentView(R.layout.ex9_data_binding);
+        Log.d(TAG, "FractionCalculator started");
+
+        /*
+        txt_enum_left = (TextView) findViewById(R.id.txt_enum_left);
+        txt_denom_left = (TextView) findViewById(R.id.txt_denom_left);
+        txt_enum_right = (TextView) findViewById(R.id.txt_enum_right);
+        txt_denom_right = (TextView) findViewById(R.id.txt_denom_right);
+        txt_enum_result = (TextView) findViewById(R.id.txt_enum_result);
+        txt_denom_result = (TextView) findViewById(R.id.txt_denom_result);
+
+        // Set all fields to 0
+        txt_enum_left.setText("0");
+        txt_denom_left.setText("0");
+        txt_enum_right.setText("0");
+        txt_denom_right.setText("0");
+        txt_enum_result.setText("0");
+        txt_denom_result.setText("0");
+        //*/
+
+    }
+
+    @Override
+    protected void onStart() {
+        super.onStart();
+
+
+
+    }
+}
diff --git a/app/src/main/res/layout/ex9_data_binding.xml b/app/src/main/res/layout/ex9_data_binding.xml
new file mode 100644
index 0000000..4fa9b3d
--- /dev/null
+++ b/app/src/main/res/layout/ex9_data_binding.xml
@@ -0,0 +1,137 @@
+<?xml version="1.0" encoding="utf-8"?>
+<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:app="http://schemas.android.com/apk/res-auto"
+    xmlns:tools="http://schemas.android.com/tools"
+    android:layout_width="match_parent"
+    android:layout_height="match_parent">
+
+    <Button
+        android:id="@+id/button_add"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:text="+"
+        app:layout_constraintEnd_toEndOf="parent"
+        app:layout_constraintStart_toStartOf="parent"
+        app:layout_constraintTop_toTopOf="parent" />
+
+    <Button
+        android:id="@+id/button_sub"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:text="-"
+        app:layout_constraintEnd_toEndOf="parent"
+        app:layout_constraintStart_toStartOf="parent"
+        app:layout_constraintTop_toBottomOf="@+id/button_add" />
+
+    <Button
+        android:id="@+id/button_mult"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:text="*"
+        app:layout_constraintEnd_toEndOf="parent"
+        app:layout_constraintStart_toStartOf="parent"
+        app:layout_constraintTop_toBottomOf="@+id/button_sub" />
+
+    <Button
+        android:id="@+id/button_div"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:text="/"
+        app:layout_constraintEnd_toEndOf="parent"
+        app:layout_constraintHorizontal_bias="0.501"
+        app:layout_constraintStart_toStartOf="parent"
+        app:layout_constraintTop_toBottomOf="@+id/button_mult" />
+
+    <TextView
+        android:id="@+id/txt_equals"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:layout_marginTop="48dp"
+        android:text="="
+        android:textSize="34sp"
+        app:layout_constraintEnd_toEndOf="parent"
+        app:layout_constraintHorizontal_bias="0.183"
+        app:layout_constraintStart_toStartOf="parent"
+        app:layout_constraintTop_toBottomOf="@+id/button_div" />
+
+    <TextView
+        android:id="@+id/txt_denom_result"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:layout_marginTop="3dp"
+        android:layout_marginBottom="412dp"
+        android:inputType="numberSigned"
+        android:numeric="integer"
+        android:text="TextView"
+        android:textAlignment="center"
+        android:textSize="34sp"
+        app:layout_constraintBottom_toBottomOf="parent"
+        app:layout_constraintEnd_toEndOf="parent"
+        app:layout_constraintHorizontal_bias="0.247"
+        app:layout_constraintStart_toEndOf="@+id/txt_equals"
+        app:layout_constraintTop_toBottomOf="@+id/txt_enum_result" />
+
+    <TextView
+        android:id="@+id/txt_enum_result"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:layout_marginTop="32dp"
+        android:numeric="integer"
+        android:text="TextView"
+        android:textAlignment="center"
+        android:textSize="34sp"
+        app:layout_constraintBottom_toTopOf="@+id/txt_denom_result"
+        app:layout_constraintEnd_toEndOf="parent"
+        app:layout_constraintHorizontal_bias="0.247"
+        app:layout_constraintStart_toEndOf="@+id/txt_equals"
+        app:layout_constraintTop_toBottomOf="@+id/button_div" />
+
+    <EditText
+        android:id="@+id/enumRight"
+        android:layout_width="140dp"
+        android:layout_height="50dp"
+        android:layout_marginTop="32dp"
+        android:ems="10"
+        android:hint="Zähler"
+        android:inputType="numberSigned"
+        app:layout_constraintEnd_toEndOf="parent"
+        app:layout_constraintStart_toEndOf="@+id/button_add"
+        app:layout_constraintTop_toTopOf="parent" />
+
+    <EditText
+        android:id="@+id/enumRight2"
+        android:layout_width="140dp"
+        android:layout_height="50dp"
+        android:layout_marginTop="32dp"
+        android:ems="10"
+        android:hint="Zähler"
+        android:inputType="numberSigned"
+        app:layout_constraintEnd_toStartOf="@+id/button_add"
+        app:layout_constraintStart_toStartOf="parent"
+        app:layout_constraintTop_toTopOf="parent" />
+
+    <EditText
+        android:id="@+id/denomLeft"
+        android:layout_width="140dp"
+        android:layout_height="50dp"
+        android:layout_marginTop="32dp"
+        android:ems="10"
+        android:hint="Nenner"
+        android:inputType="number"
+        app:layout_constraintEnd_toStartOf="@+id/button_mult"
+        app:layout_constraintStart_toStartOf="parent"
+        app:layout_constraintTop_toBottomOf="@+id/enumRight2" />
+
+    <EditText
+        android:id="@+id/denomRight"
+        android:layout_width="140dp"
+        android:layout_height="50dp"
+        android:layout_marginTop="32dp"
+        android:ems="10"
+        android:hint="Nenner"
+        android:inputType="number"
+        app:layout_constraintEnd_toEndOf="parent"
+        app:layout_constraintStart_toEndOf="@+id/button_mult"
+        app:layout_constraintTop_toBottomOf="@+id/enumRight" />
+
+</androidx.constraintlayout.widget.ConstraintLayout>
\ No newline at end of file