diff --git a/.idea/gradle.xml b/.idea/gradle.xml
index 18de3ac5fd2f22fdca07daa01d5bb995c8802d25..23a89bbb6ca829a47211d20c8b11960088ea4950 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/app/src/main/java/com/zybooks/pizzaparty/MainActivity.java b/app/src/main/java/com/zybooks/pizzaparty/MainActivity.java
index b9b8ec6ffcebe111de900954051a3b10d53fd4e8..7f122ed5eaca0711dea0593795221b3fe2400b83 100644
--- a/app/src/main/java/com/zybooks/pizzaparty/MainActivity.java
+++ b/app/src/main/java/com/zybooks/pizzaparty/MainActivity.java
@@ -3,12 +3,18 @@
 package com.zybooks.pizzaparty;
 
 import android.os.Bundle;
+import android.text.Editable;
+import android.text.TextWatcher;
 import android.view.View;
+import android.widget.AdapterView;
+import android.widget.ArrayAdapter;
 import android.widget.EditText;
 import android.widget.RadioGroup;
 import android.widget.TextView;
 import androidx.appcompat.app.AppCompatActivity;
 import android.util.Log;
+import android.widget.Spinner;
+import android.widget.Toast;
 
 public class MainActivity extends AppCompatActivity {
 
@@ -16,7 +22,7 @@ public class MainActivity extends AppCompatActivity {
 
     private EditText mNumAttendEditText;
     private TextView mNumPizzasTextView;
-    private RadioGroup mHowHungryRadioGroup;
+    private Spinner mHowHungrySpinner;
 
     private final static String TAG = "MainActivity";
 
@@ -30,7 +36,44 @@ public class MainActivity extends AppCompatActivity {
         // Assign the widgets to fields
         mNumAttendEditText = findViewById(R.id.attendEditText);
         mNumPizzasTextView = findViewById(R.id.answerTextView);
-        mHowHungryRadioGroup = findViewById(R.id.hungryRadioGroup);
+        mHowHungrySpinner = findViewById(R.id.hunger_spinner);
+
+        // Watch for changes to number attending
+        mNumAttendEditText.addTextChangedListener(new TextWatcher() {
+            @Override
+            public void beforeTextChanged(CharSequence s, int start, int count, int after) {
+
+            }
+
+            @Override
+            public void onTextChanged(CharSequence s, int start, int before, int count) {
+
+            }
+
+            @Override
+            public void afterTextChanged(Editable s) {
+                mNumPizzasTextView.setText("");
+            }
+        });
+
+        // set up the hunger spinner
+        ArrayAdapter<CharSequence> adapter = ArrayAdapter.createFromResource(this,
+                R.array.hunger_array, android.R.layout.simple_spinner_item);
+        adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
+        mHowHungrySpinner.setAdapter(adapter);
+        mHowHungrySpinner.setSelection(0,false);
+        mHowHungrySpinner.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
+            @Override
+            public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
+                String item = (String)parent.getItemAtPosition(position);
+                Toast.makeText(MainActivity.this, item, Toast.LENGTH_SHORT).show();
+                mNumPizzasTextView.setText("");
+            }
+
+            @Override
+            public void onNothingSelected(AdapterView<?> parent) {
+            }
+        });
     }
 
     public void calculateClick(View view) {
@@ -40,18 +83,17 @@ public class MainActivity extends AppCompatActivity {
         try {
             String numAttendStr = mNumAttendEditText.getText().toString();
             numAttend = Integer.parseInt(numAttendStr);
-        }
-        catch (NumberFormatException ex) {
+        } catch (NumberFormatException ex) {
             numAttend = 0;
         }
 
         // Get hunger level selection
-        int checkedId = mHowHungryRadioGroup.getCheckedRadioButtonId();
+        int checkedId = mHowHungrySpinner.getId(); // I didn't know what to do after updating to mHowHungrySpinner
         PizzaCalculator.HungerLevel hungerLevel = PizzaCalculator.HungerLevel.RAVENOUS;
-        if (checkedId == R.id.lightRadioButton) {
+        if (checkedId == R.id.hunger_spinner) {
             hungerLevel = PizzaCalculator.HungerLevel.LIGHT;
         }
-        else if (checkedId == R.id.mediumRadioButton) {
+        else if (checkedId == R.id.hunger_spinner) {
             hungerLevel = PizzaCalculator.HungerLevel.MEDIUM;
         }
 
diff --git a/app/src/main/res/layout/activity_main.xml b/app/src/main/res/layout/activity_main.xml
index 5f74b29f79867fa7f8edc5e6deb8c0fc6a32f2ac..a16a700e7f4e6d0d5305948939e3bf107b15f7fe 100644
--- a/app/src/main/res/layout/activity_main.xml
+++ b/app/src/main/res/layout/activity_main.xml
@@ -1,63 +1,54 @@
 <?xml version="1.0" encoding="utf-8"?>
-<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
+<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:id="@+id/activity_main"
-    android:background="@drawable/pizza_background"
+
     android:layout_width="match_parent"
     android:layout_height="match_parent"
-    android:orientation="vertical"
-    android:paddingBottom="16dp"
-    android:paddingLeft="16dp"
-    android:paddingRight="16dp"
-    android:paddingTop="16dp"
     tools:context="com.zybooks.pizzaparty.MainActivity">
 
     <TextView
+        android:id="@+id/numberLabel"
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
+        android:labelFor="@id/attendEditText"
         android:text="@string/number_of_people"
         android:textSize="@dimen/label_text_size"
-        android:labelFor="@id/attendEditText" />
+        app:layout_constraintLeft_toLeftOf="parent"
+        app:layout_constraintTop_toTopOf="parent" />
+
 
     <EditText
         android:id="@+id/attendEditText"
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
         android:inputType="number"
+        android:layout_marginLeft="5dp"
         android:ems="5"
         android:importantForAutofill="no"
-        android:hint="@string/_10" />
+        android:hint="@string/_10"
+        app:layout_constraintLeft_toRightOf="@id/numberLabel"
+        app:layout_constraintBaseline_toBaselineOf="@id/numberLabel"/>
 
     <TextView
+        android:id="@+id/hungryLabel"
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
-        android:layout_marginTop="20dp"
+        android:layout_marginTop="25dp"
         android:text="@string/how_hungry"
         android:textSize="24sp"
-        android:labelFor="@id/hungryRadioGroup" />
+        app:layout_constraintLeft_toLeftOf="parent"
+        app:layout_constraintTop_toBottomOf="@id/numberLabel"
+        android:labelFor="@id/hunger_spinner" />
 
-    <RadioGroup
-        android:id="@+id/hungryRadioGroup"
-        android:layout_width="fill_parent"
+    <Spinner
+        android:id="@+id/hunger_spinner"
+        android:layout_width="wrap_content"
         android:layout_height="wrap_content"
-        android:orientation="vertical">
-        <RadioButton
-            android:id="@+id/lightRadioButton"
-            android:text="@string/light"
-            android:layout_width="wrap_content"
-            android:layout_height="wrap_content" />
-        <RadioButton
-            android:id="@+id/mediumRadioButton"
-            android:text="@string/medium"
-            android:layout_width="wrap_content"
-            android:layout_height="wrap_content"
-            android:checked="true" />
-        <RadioButton
-            android:id="@+id/ravenousRadioButton"
-            android:text="@string/ravenous"
-            android:layout_width="wrap_content"
-            android:layout_height="wrap_content" />
-    </RadioGroup>
+        app:layout_constraintLeft_toRightOf="@id/hungryLabel"
+        app:layout_constraintBaseline_toBaselineOf="@id/hungryLabel"/>
 
     <TextView
         android:id="@+id/answerTextView"
@@ -65,7 +56,10 @@
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
         android:layout_marginTop="20dp"
-        android:textSize="24sp"/>
+        android:textSize="24sp"
+        app:layout_constraintLeft_toRightOf="parent"
+        app:layout_constraintTop_toBottomOf="@id/hunger_spinner"
+        android:layout_marginLeft="5dp"/>
 
     <Button
         android:id="@+id/calcButton"
@@ -73,5 +67,8 @@
         android:layout_width="match_parent"
         android:layout_height="wrap_content"
         android:layout_marginTop="20dp"
-        android:onClick="calculateClick" />
-</LinearLayout>
\ No newline at end of file
+        android:onClick="calculateClick"
+        app:layout_constraintLeft_toLeftOf="parent"
+        app:layout_constraintTop_toBottomOf="@id/answerTextView"
+        style="@style/CalcButton"/>
+</androidx.constraintlayout.widget.ConstraintLayout>
\ No newline at end of file
diff --git a/app/src/main/res/values/colors.xml b/app/src/main/res/values/colors.xml
index aa80c443a430391c1cea8dc229930ad369e24951..d8be17d2da179c29a2a1707a80ac857f359aef9c 100644
--- a/app/src/main/res/values/colors.xml
+++ b/app/src/main/res/values/colors.xml
@@ -8,4 +8,5 @@
     <color name="black">#FF000000</color>
     <color name="white">#FFFFFFFF</color>
     <color name="my_green">#11BB11</color>
+    <color name="gray">#AAA</color>
 </resources>
\ No newline at end of file
diff --git a/app/src/main/res/values/strings.xml b/app/src/main/res/values/strings.xml
index e85abf7a14a24749a1e77b8e8024836dfd4d23a9..37d0f7c3cfeee0d24b8957d6c32c346745d4c101 100644
--- a/app/src/main/res/values/strings.xml
+++ b/app/src/main/res/values/strings.xml
@@ -8,4 +8,9 @@
     <string name="ravenous">Ravenous</string>
     <string name="total_pizzas">Total pizzas: %d</string>
     <string name="calculate">Calculate</string>
+    <string-array name="hunger_array">
+        <item>Light</item>
+        <item>Medium</item>
+        <item>Ravenous</item>
+    </string-array>
 </resources>
\ No newline at end of file
diff --git a/app/src/main/res/values/styles.xml b/app/src/main/res/values/styles.xml
new file mode 100644
index 0000000000000000000000000000000000000000..7dd156abaa7342bb6f546e4e0b1ae77380cf2f26
--- /dev/null
+++ b/app/src/main/res/values/styles.xml
@@ -0,0 +1,7 @@
+<?xml version="1.0" encoding="utf-8"?>
+<resources>
+    <style name="CalcButton">
+        <item name="android:textSize">24sp</item>
+        <item name="android:textColor">@color/gray</item>
+    </style>
+</resources>
\ No newline at end of file