I'll tell you then. It was worth 1/96th of a Gulden. How? Well, the first thing to explain is that the "5" should really have been a "6". They noticed the error relatively late, by then the coins were already on their way across the ocean. As transport was slow back then and they needed coins badly, they decided they'd use them anyway.
The second thing to explain is that the meaning is "6 of this coin equals 1/16 of a Gulden". So 1/16 divided by 6 and you have the correct value. Have never seen any other coins with this kind of denomination (apart from the 5 - 1/32 from the same production line, worth exactly half of the other one).