Having difficulty learning how to use methods with everything else I've learned in my first 4 weeks of java. I'm stuck on this last problem

Write a method qualityPoints that inputs a students average and returns 4 if its 90100, 3 if 8089, 2 if 7079, 1 if 6069 and 0 if lower than 60. Incorporate the method into an application that reads a value from the user and displays the result.

As a beginner I would appreciate help with the code and I'd like to ask questions about any lines I don't fully understand!