Q: Is it good practice to create static methods in MainActivity in Android? I have a simple function that receives an integer 'cents' and returns a String with a decimal point between the units and the cents.
 1000 --> String function(int cents) --> "10.00"

This function is used extensively throughout the application and I am looking for a way not to replicate the code everywhere I use it. 
I have thought of including this function as a static method inside MainActivity and then calling it like this:
 MainActivity.function();

Another possibility I have considered is creating an Object using the Singleton Pattern and accessing this function through it. 
What are the best practices concerning this problem? 
