AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.funmathv2">

    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/Theme.FunMathV2">
        <activity android:name=".SubtractionAdvIncorrect"></activity>
        <activity android:name=".SubtractionAdvCorrect" />
        <activity android:name=".SubtractionAdv" />
        <activity android:name=".SubtractionBasicIncorrect" />
        <activity android:name=".SubtractionBasicCorrect" />
        <activity android:name=".SubtractionBasic" />
        <activity android:name=".DivisionBasic" />
        <activity android:name=".AdditionAdvIncorrect" />
        <activity android:name=".AdditionAdvCorrect" />
        <activity android:name=".AdditionAdv" />
        <activity android:name=".AdditionBasicIncorrect" />
        <activity android:name=".AdditionBasicCorrect" />
        <activity android:name=".AdditionBasic" />
        <activity android:name=".DivisionMenu" />
        <activity android:name=".MultiplicationMenu" />
        <activity android:name=".SubtractionMenu" />
        <activity android:name=".AdditionMenu" />
        <activity android:name=".MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>