converting timer countdown to only show minute and seconds

So I’m using C# and have a count down timer, if the timer hits 0 then the player dies.
i have a timer working but its showing seconds and milliseconds only (e.g. 6.5377) i need to change it to only show minute and seconds. the time shows up on my GUI just fine (other than showing seconds/milliseconds)
This is the code for the timer

public float timeRemaining = 120;
	void Update () 
	{
		if (timeRemaining <=0)
		{
			timeRemaining =0;
		}
		timeRemaining-=Time.deltaTime;
	}
and this is the code for the GUI to show
public Text timeRemaining;
	public GameObject countDownRef;
void Update()
{
timeRemaining.text= countDownRef.GetComponent().timeRemaining.ToString();
}

What your looking for is the math operation mod.
The mod symbol is %.
You would do: seconds = totalseconds % 60; to calculate the seconds,
and minutes = Mathf.Round(totalseconds / 60) to calculate the minutes;

So you would do this:

timeremaining.text = Mathf.Round(totalseconds/60) + “:” + totalseconds % 60;