Simplify the following text for a Grade 8 native English-speaking person.
Original: ARD 's constituent broadcasting institutions -- BR , HR , MDR , NDR , Radio Bremen , RBB , SR , SWR , and WDR ( see below for an explanation of the abbreviations ) , as well as international broadcaster Deutsche Welle -- operate 54 regional and local radio stations and networks , two nationwide radio channels , and seven regional TV networks , some of which split further during certain parts of the day .
Simplified: They make a total of 54 regional and local radio stations and networks , two nationwide radio channels , and seven regional TV networks . During certain parts of the day some of these split even further .