How do I receive data (int.) from another Activity?

Question

I researched several posts here on stackoverflow and I found none talking about migrating whole numbers, I tried a lot of things but it didn’t work out. I’m a beginner and I probably missed something silly, but I can’t see what it is.

I am putting together a quiz, with several activitys and wanted to make a score that was adding up 1 point for each right question of each Activity.

Follow my code that is not working. If anyone can help me, I am grateful at once.

Activity 1

public class A_Activity extends AppCompatActivity {

TextView score;
int mScore = 0;

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

    score = (TextView) findViewById(R.id.score);
    score.setText("Score: " + mScore);

}

public void onClickTrue(View v) {
    mScore++;
    score.setText("Score: " + mScore);

    Intent i = new Intent(this, B_Activity.class);

    Bundle params = new Bundle();
    params.putInt("mScore", mScore);
    i.putExtras(params);
    startActivity(i);
}

Activity 2 (reception desk)

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

    Intent i = getIntent();
        if (i != null){
            Bundle params = i.getExtras();

            if (params != null){
                String mScore = params.getString("mScore");

                }

        }

}