בונים את המסכים של Basic Views Activity

 <resources>
-    <string name="app_name">ScoreCounter</string>
+    <string name="app_name">מונה נקודות</string>
+    <string name="score_add">הוספת נקודה</string>
+    <string name="score_subtract">הפחתת נקודה</string>
 </resources>

     tools:context=".MainActivity">

-    <TextView
-        android:layout_width="wrap_content"
+    <LinearLayout
+        android:layout_width="0dp"
         android:layout_height="wrap_content"
-        android:text="Hello World!"
-        app:layout_constraintBottom_toBottomOf="parent"
+        android:gravity="center_horizontal"
+        android:orientation="vertical"
+        android:padding="16dp"
         app:layout_constraintEnd_toEndOf="parent"
         app:layout_constraintStart_toStartOf="parent"
-        app:layout_constraintTop_toTopOf="parent" />
+        app:layout_constraintTop_toTopOf="parent">
+
+        <TextView
+            android:id="@+id/textview_score"
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content"
+            android:textSize="32sp"
+            tools:text="0" />
+
+        <Button
+            android:id="@+id/button_plus"
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content"
+            android:text="@string/score_add" />
+
+        <Button
+            android:id="@+id/button_minus"
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content"
+            android:text="@string/score_subtract" />
+    </LinearLayout>

 </androidx.constraintlayout.widget.ConstraintLayout>

     private ActivityMainBinding binding;
+    private int score = 0;

     @Override

             return insets;
         });
+
+        binding.buttonPlus.setOnClickListener(v -> {
+            score++;
+            showScore();
+        });
+        binding.buttonMinus.setOnClickListener(v -> {
+            score--;
+            showScore();
+        });
+        showScore();
+    }
+
+    /** Displays the current score in the score label. */
+    private void showScore() {
+        binding.textviewScore.setText(String.valueOf(score));
     }
 }

     tools:context=".MainActivity">

+    <com.google.android.material.appbar.MaterialToolbar
+        android:id="@+id/toolbar"
+        android:layout_width="0dp"
+        android:layout_height="?attr/actionBarSize"
+        app:layout_constraintEnd_toEndOf="parent"
+        app:layout_constraintStart_toStartOf="parent"
+        app:layout_constraintTop_toTopOf="parent" />
+
     <LinearLayout
         android:layout_width="0dp"

         app:layout_constraintEnd_toEndOf="parent"
         app:layout_constraintStart_toStartOf="parent"
-        app:layout_constraintTop_toTopOf="parent">
+        app:layout_constraintTop_toBottomOf="@id/toolbar">

         <TextView

         binding = ActivityMainBinding.inflate(getLayoutInflater());
         setContentView(binding.getRoot());
+        setSupportActionBar(binding.toolbar);
         ViewCompat.setOnApplyWindowInsetsListener(binding.main, (v, insets) -> {
             Insets systemBars = insets.getInsets(WindowInsetsCompat.Type.systemBars());

 constraintlayout = "2.2.2"

+navigation = "2.10.2"
+
 [libraries]
 junit = { group = "junit", name = "junit", version.ref = "junit" }

 constraintlayout = { group = "androidx.constraintlayout", name = "constraintlayout", version.ref = "constraintlayout" }

+navigation-fragment = { group = "androidx.navigation", name = "navigation-fragment", version.ref = "navigation" }
+navigation-ui = { group = "androidx.navigation", name = "navigation-ui", version.ref = "navigation" }
+
 [plugins]
 android-application = { id = "com.android.application", version.ref = "agp" }
-

     implementation(libs.constraintlayout)
     implementation(libs.material)
+    implementation(libs.navigation.fragment)
+    implementation(libs.navigation.ui)
     testImplementation(libs.junit)
     androidTestImplementation(libs.espresso.core)

 import androidx.core.view.ViewCompat;
 import androidx.core.view.WindowInsetsCompat;
+import androidx.navigation.NavController;
+import androidx.navigation.fragment.NavHostFragment;
+import androidx.navigation.ui.AppBarConfiguration;
+import androidx.navigation.ui.NavigationUI;

 import com.example.scorecounter.databinding.ActivityMainBinding;

     private ActivityMainBinding binding;
-    private int score = 0;
+    private AppBarConfiguration appBarConfiguration;

     @Override

         });

-        binding.buttonPlus.setOnClickListener(v -> {
-            score++;
-            showScore();
-        });
-        binding.buttonMinus.setOnClickListener(v -> {
-            score--;
-            showScore();
-        });
-        showScore();
+        NavController navController = getNavController();
+        appBarConfiguration = new AppBarConfiguration.Builder(navController.getGraph()).build();
+        NavigationUI.setupActionBarWithNavController(this, navController, appBarConfiguration);
     }

-    /** Displays the current score in the score label. */
-    private void showScore() {
-        binding.textviewScore.setText(String.valueOf(score));
+    /** Returns the controller from the NavHostFragment declared in activity_main.xml. */
+    private NavController getNavController() {
+        NavHostFragment host = (NavHostFragment) getSupportFragmentManager()
+                .findFragmentById(R.id.nav_host);
+        return host.getNavController();
     }
 }

     <string name="score_add">הוספת נקודה</string>
     <string name="score_subtract">הפחתת נקודה</string>
+    <string name="rules_title">איך משחקים</string>
+    <string name="rules_text">לחצו על הוספת נקודה כדי להעלות את הניקוד ועל הפחתת נקודה כדי להוריד אותו.</string>
+    <string name="return_to_score">חזרה למונה</string>
 </resources>

         android:id="@+id/firstFragment"
         android:name="com.example.scorecounter.FirstFragment"
-        android:label="@string/app_name" />
+        android:label="@string/app_name">
+        <action
+            android:id="@+id/action_first_to_second"
+            app:destination="@id/secondFragment" />
+    </fragment>
+
+    <fragment
+        android:id="@+id/secondFragment"
+        android:name="com.example.scorecounter.SecondFragment"
+        android:label="@string/rules_title" />
 </navigation>

             android:layout_height="wrap_content"
             android:text="@string/score_subtract" />
+
+        <Button
+            android:id="@+id/button_rules"
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content"
+            android:layout_marginTop="16dp"
+            android:text="@string/rules_title" />
     </LinearLayout>
 </androidx.core.widget.NestedScrollView>

 import androidx.annotation.NonNull;
 import androidx.fragment.app.Fragment;
+import androidx.navigation.fragment.NavHostFragment;

 import com.example.scorecounter.databinding.FragmentFirstBinding;

             showScore();
         });
+        binding.buttonRules.setOnClickListener(v ->
+                NavHostFragment.findNavController(this).navigate(R.id.action_first_to_second));
         showScore();
     }

     }

+    /** Handles the app bar's Up arrow using the same navigation graph as Back. */
+    @Override
+    public boolean onSupportNavigateUp() {
+        return NavigationUI.navigateUp(getNavController(), appBarConfiguration)
+                || super.onSupportNavigateUp();
+    }
+
     /** Returns the controller from the NavHostFragment declared in activity_main.xml. */
     private NavController getNavController() {

     <string name="rules_text">לחצו על הוספת נקודה כדי להעלות את הניקוד ועל הפחתת נקודה כדי להוריד אותו.</string>
     <string name="return_to_score">חזרה למונה</string>
+    <string name="help_button">עזרה קצרה</string>
+    <string name="help_message">פלוס מוסיף נקודה ומינוס מפחית נקודה.</string>
+    <string name="menu_about">אודות</string>
+    <string name="about_message">מונה נקודות — תרגיל Android לכיתה י״א</string>
 </resources>

         app:navGraph="@navigation/nav_graph" />

+
+    <com.google.android.material.floatingactionbutton.FloatingActionButton
+        android:id="@+id/fab"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:layout_margin="16dp"
+        android:contentDescription="@string/help_button"
+        app:layout_constraintBottom_toBottomOf="parent"
+        app:layout_constraintEnd_toEndOf="parent"
+        app:srcCompat="@android:drawable/ic_menu_help" />
 </androidx.constraintlayout.widget.ConstraintLayout>

 import android.os.Bundle;
+import android.view.Menu;
+import android.view.MenuItem;

 import androidx.activity.EdgeToEdge;

 import com.example.scorecounter.databinding.ActivityMainBinding;
+import com.google.android.material.snackbar.Snackbar;
 public class MainActivity extends AppCompatActivity {

         appBarConfiguration = new AppBarConfiguration.Builder(navController.getGraph()).build();
         NavigationUI.setupActionBarWithNavController(this, navController, appBarConfiguration);
+
+        binding.fab.setOnClickListener(view -> showMessage(R.string.help_message));
+    }
+
+    /** Adds the About item to the toolbar's overflow menu. */
+    @Override
+    public boolean onCreateOptionsMenu(Menu menu) {
+        getMenuInflater().inflate(R.menu.menu_main, menu);
+        return true;
+    }
+
+    /** Shows the app's About message when its menu item is selected. */
+    @Override
+    public boolean onOptionsItemSelected(MenuItem item) {
+        if (item.getItemId() == R.id.action_about) {
+            showMessage(R.string.about_message);
+            return true;
+        }
+        return super.onOptionsItemSelected(item);
+    }
+
+    /** Shows a short message above the floating action button. */
+    private void showMessage(int message) {
+        Snackbar.make(binding.getRoot(), message, Snackbar.LENGTH_LONG)
+                .setAnchorView(binding.fab).show();
     }