How do I increase the value of a number in my text with C#

Questions & Answers
1

How can I increase the value of a number in my text with C#, like score, constantly increasing. In my Update. Here:
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.UI;

public class Score : MonoBehaviour {

	public PlayerController player;
	public Text gameText;
	public float score = 0;
	// Use this for initialization
	void Start () {

	}

	// Update is called once per frame
	void FixedUpdate () {
		
		gameText.text = "Time : " + player.score;
		score += 2;
	}
}
2

public PlayerController player;
public Text gameText;
public float interval = 1f; // 1 second

private float _t;

void Update()
{
	if(_t < interval)
		_t += Time.deltaTime;
	else
	{
		_t -= interval;								// reset timer
		player.score += 2;							// increase a player score
		gameText.text = "Time : " + player.score;	// udpate the text
	}
}