public class activity_game extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_game);

        final NumberPicker fizzNumberPkr = (NumberPicker)findViewById(fizzNumberPicker);
        fizzNumberPkr.setValue(3);
        fizzNumberPkr.setMinValue(1);
        fizzNumberPkr.setMaxValue(20);
        fizzNumberPkr.setWrapSelectorWheel(true);
        final NumberPicker buzzNumberPkr = (NumberPicker)findViewById(buzzNumberPicker);
        buzzNumberPkr.setValue(5);
        buzzNumberPkr.setMinValue(1);
        buzzNumberPkr.setMaxValue(20);
        buzzNumberPkr.setWrapSelectorWheel(true);

    }

    public void toActivityPlay (View view) {
        Intent toActivityPlay = new Intent(this, activity_play.class);
        toActivityPlay.putExtra("fizzNumber", fizzNumber);
        toActivityPlay.putExtra("buzzNumber", buzzNumber);
        startActivity(toActivityPlay);
    }

public class activity_play extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_play);

        TextView fizzNumberText = (TextView)findViewById(R.id.fizzNumber);
        fizzNumberText.setText(getIntent().getExtras().getString("fizzNumber"));

        if(getIntent().hasExtra("fizzNumber")) {
            fizzNumber = getIntent().getIntArrayExtra();
        } else {
            throw new IllegalArgumentException("Error: Fizz number not found");
        }