Generate Fixed Distance String

Right now I am working on calculating distance that object travel in generating distance I have no problem. It works perfect as expected but to display it on screen become difficult for me.

Basically I want distance displayed as '00013', in this format alway want to prefix '0' for each calculated distance. For this I write this type of code but I know it is poor piece of coding.

         if(GameManager.Instance.DistanceTraveled <10)
             distanceText.text = "000" + Mathf.Ceil(GameManager.Instance.DistanceTraveled);
         else if(GameManager.Instance.DistanceTraveled <100)
             distanceText.text = "00" + Mathf.Ceil(GameManager.Instance.DistanceTraveled);
         else if(GameManager.Instance.DistanceTraveled <1000)
             distanceText.text = "0" + Mathf.Ceil(GameManager.Instance.DistanceTraveled);

I want some great way to display distance string with any type of if ladder. Please give some guidance in this.