Calling a function within a Class method?

I have been trying to figure out how to go about doing this but I am not quite sure how.

Here is an example of what I am trying to do:

class test {
     public newTest(){
          function bigTest(){
               //Big Test Here
          }
          function smallTest(){
               //Small Test Here
          }
     }
     public scoreTest(){
          //Scoring code here;
     }
}

Here is the part I am having problems with, how do I call bigTest()?