you are speaking about _one directional consecutive rides_

I.e. 10 rides are just 5 trips

if you have a ride home from work and take some side route to stop at a shopping mall or Kino or so that counts as an additional trip

but someone using it for work daily tends to have more then 42 rides a month not just 10 and that is just for work transit in a 5 work day week

and then this is assuming you only travel in the AB area and not the outer area of Berlin

and there are many (in summer) nice places close by Berlin, some still in the C area some beyond

lastly, it's very convenient, I mean since I don't have a semester ticket anymore I forgot to buy a ticket way to often and just was lucky to never got cought