 
| 29.3.3 Zu 
                        dritt, zu viert, zu fünft, zu sechst | 
This
 -t  does not justify a declension. The morpheme 
-t 
                        is an expression and with cardinal numbers it means 
                        of us/them. 
 
| Zu dritt, zu viert, zu fünft, zu sechst |  |  | 
| zu zweit | = two of us / them |  | 
| zu dritt | = three of us / them |  | 
| zu viert | = four of us / them |  | 
| zu fünft | = five of us / them |  | 
| zu sechst | = six of us / them |  | 
| Let's have a look at some examples |  | 
| Sie 
                                    gingen zu 
                                    dritt zum Bürgermeisteramt. = Three of them went to the mayor's office.
 
 |  | 
| Sie 
                                    machten es zu 
                                    viert. = They were four of them who did it.
 
 |  |