How many different scripts do I need to write to create a highscore system?

I am trying to create a single highscore on Android OS that displays in my first scene and is saved there so when the player returns their highscore is saved and displayed. I'm just trying to get a handle on the order of things. Thanx

Generally:

How many separate scripts will it take to accomplish this?

How many empty game objects will I need to create for these scripts if any?

How many GUiText objects will I need?

Can all of my scripts lay on one game Object to complete this task?

Thanx again.

This is my current score script which sits on a GUIText Object in my second scene and it works perfectly.

` var r : float = 1;

 var g : float = 0;
 
 var b : float = 0;
 
 var a : float = 1;
 
 static var Score : int = 0;
 
 
 function Start(){
    
 
 
          Score+=100;
          guiText.text = "Score: "+Score;
      
          var color : Color = Color (r, g, b, a);
           // Change the material to display green text.
             guiText.material.color = color;
         
         
     }
 
 function AddPoints() {
         
         Score+=100;
         guiText.text = "Score: "+Score;
     
      
 } 
 
 
 
 function Awake() {
 
         Score = 0;
 }
 
 function Reset(){
 
         Score = 1400;
 }