Adding variable not work in an extended script

I want to make scripts for the pause menu. I make two scripts for that. One of it is to generate pause menu which is a parent script: using UnityEngine; using System.Collections;

 public class GameScene1BackButton : MonoBehaviour {
 
     public Object pauseMenuPrefab;
     public int pausedTime;
 
     void Awake () {
         pausedTime = 0;
     }
 
     // Update is called once per frame
     void Update () {
         if (Input.GetKeyDown (KeyCode.Escape)) {
             if (pausedTime % 2 == 0) {
                 Pause ();
             }
         }
         if (Input.GetKeyDown (KeyCode.P)) {
             if (pausedTime % 2 == 0) {
                 Pause ();
             }
         }
         Debug.Log (pausedTime);
     }
 
     public void Pause () {
         pausedTime++;
         Time.timeScale = 0.0f;
         Instantiate (pauseMenuPrefab, new Vector3(0.01042994f, -0.07116497f, 0f), Quaternion.identity);
     }
 
     public void ExitPause () {
         Time.timeScale = 1.0f;
         pausedTime++;
         Destroy (GameObject.Find ("PauseMenu(Clone)"));
     }
 
 }

Another one is an extended script which is for the button in the pause menu:

 using UnityEngine;
 using System.Collections;
 
 public class BackToGame : GameScene1BackButton {
     
     // Update is called once per frame
     void Update () {
         if (Input.touches.Length <= 0) {
             
         } else {
             for (int i = 0; i < Input.touchCount; i++) {
                 if (this.guiTexture.HitTest (Input.GetTouch (i).position)) {
                     if (Input.GetTouch (i).phase == TouchPhase.Ended) {
                         ExitPause ();
                     }
                 }
             }
         }
     }
 
     void OnMouseDown () {
         ExitPause ();
     }
 
 }

I make a variable pausedTime for finding when I push the button, the pause menu will generate or not. As ExitPause () will be worked in another script, pausedTime++ will also be done in another script. But when the back to game button is pressed, pauseTime does not add up. How to make pauseTime add to make it work?