adding time to int

hi i am trying to make a semi-realistic bird flight code, but i am having an issue where when i try to add an int value of the time to the available wing flaps after the first initial period it instantly increases by each part of a second instead of the 2 seconds it should be, simpler it is meant to add 1 to flaps for every 2 seconds you are gliding instead after the first 2 seconds it just increases almost instantly. Here is the code. if this can be done easier using javascript please say so and give an example, still learning c# and haven't started with javascript, i have prior knowledge of software coding from software development classes, but that was using visual basic.

 private Rigidbody rb;
     public Text glidetime;
     public Text flapnum;
     public Text StateCheck;
     public bool grounded = true;
     public float timePressed = 0f;
     public float currentTime;
     public float rest;
     private int flaps;
     private int flaps2;
     private int flaps3;
     
     void Start()
     {
         rb = GetComponent<Rigidbody>();
         flaps = 10;
         setflaptext();
         setglidetext();
     }
 
     
     void Update()
     {
         glideTimer();
         glide();
         fly();
         flaps3 = flaps;
         if (!grounded && rb.velocity.y == 0)
         {
             grounded = true;
             StateCheck.text = rb.velocity.y.ToString();
         }
 
         if (Input.GetButtonDown("Jump") && grounded == true)
         {
 
             rb.velocity += new Vector3(0.0f, 20.0f, 0.0f);
             grounded = false;
             StateCheck.text = rb.velocity.y.ToString();
         }
         //if (Input.GetButton("Fire1"))
         //{
         //    flaps = 
         //}
     }
 
     void FixedUpdate()
     {
 
     }
 
     // glidetimer is used to check the length of the time gliding and increase the number of flaps by a set variable
     void glideTimer()
     {
         if (grounded == false)
         {
             if (Input.GetButton("Fire1") && timePressed < 10)
             {
                 timePressed += Time.deltaTime;
                 currentTime = timePressed;
                 rest = (int)currentTime;
                 flaps = flaps3 + (int)currentTime / 2;
                 setglidetext();
                 setflaptext();
             }
         }
      }
 
     // glide is the physics of the glide control
     void glide()
     {
         if (Input.GetButton("Fire1") && grounded == false)
         {
             rb.drag = 15;
         }
         if (Input.GetButtonUp("Fire1"))
         {
             rb.drag = 0;
         }
     }
 
     void fly()
     {
         if (flaps > 0)
         {
             if (Input.GetButtonDown("Jump") && grounded == false)
             {
                 rb.velocity += new Vector3(0.0f, 10.0f, 0.0f);
                 flaps = flaps - 1;
                 flaps2 = flaps;
                 timePressed = 0;
                 currentTime = 0;
                 setflaptext();
                 setglidetext();
             }
             else if (flaps > 10)
             {
                 flaps = 10;
             }
         }
     }
 
     void setflaptext()
     {
         flapnum.text = "Flaps: " + flaps.ToString();
     }
 
     void setglidetext()
     {
         glidetime.text = "Glide time: " + currentTime.ToString();
     }