You are mistaking this for the probability for a set of events. An event in this case is a roll on a dice - 1/6th chance to roll a number. The chance never changes. BUT the chance of rolling any other number decreases the more you add the events into the set. But that's the probability for the whole set.

Set of 1 roll is 5/6 (times 100 if you wanna see it in % ) which is roughly 83,33 %

But set of 10 rolls (any other than 6) is 5/6 ^ 10 which is roughly 16,15 %

Now from this it seems like the chance is getting bigger, but what's changing is the set you're tracking probability for. The rolls are still 1/6th for a number :)

edit> to give you maybe a better example considering my English and explanation skills :D

if you roll 9 times any other number than 6, then the next roll being any other number while considering the whole set is 16,15 % and the roll for the 6 thus increased to awesome 83,85 %! But that's ONLY because we make the probability based on the previous rolls. The chance the next roll will be any other number on its own is still 5/6 and the chance for the 6 is still 1/6.