How to properly change variables of a sub class

Hi! I wrote some code with a class and a subclass:

 public class Units : MonoBehaviour
 {
     public int movementPoints = 0;
     public int HP = 0;
 }

and the subclass:

 public class IceBreaker : Units
 {
     private void Awake()
     {
         HP = 100;
         movementPoints = 2;
     }
 }

now in a different piece of code I have the function:

 public void AddShip(Units unit)
 { 
     print(unit.GetType());
     print(unit.HP);
 }

the unit.GetType() will always result in IceBreaker when I print it, but unit.HP will always result in 0. The inspector says the HP of my Icebreaker is 100, however. I'm assuming that unit.HP results in the code grabbing the HP value of the Unit class, but I have no clue how to fix this.