1. Initiate the native Contacts app.
2. Tap on the "+" symbol.
3. After adding the person's name, tap on the "+" symbol in front of "add phone".
4. Choose if the number will be a home, iPhone, mobile, work, etc., number and then add the phone number.
5. Select "Done" when you're finished.
Now select that particular contact and see if the phone number appears in it's entirety. It should.