Tram
I learned how to take the tram into town.  I got my money's worth because when I transferred trams I got on the correct tram but going the wrong way.  So, I got to see more of the city.  Next we need to get monthly passes to make it cost less.

We both now have a monthly pass so we can take the local Mannheim trams and buses as much as we need too.  That saves a lot and it is very convenient to not have to buy multiple passes each day.  Each ride is 2.30 euros.  A monthly pass costs 60 euros.