Complex sentence: On January 8,1994, the area served by 215 was split, with the western suburbs and most of Berks County and the Lehigh Valley changing to area code 610, while Philadelphia and its northern suburbs remained 215.
Split into simpler sentences: On January 8,1994, the area served by 215 was split. The southern and western suburbs, most of Berks County and the Lehigh Valley changed to area code 610, while Philadelphia and its northern suburbs remained 215.