Counting large numbers in 1 second by increment by +1

@CrispyDev How I would go with this is using booleans and Coroutines heres a example

 public int Number = 0;
 bool hasPassed = false;
 public void Update()
 {
     if (hasPassed == false)
     {
         Number++;
         StartCoroutine(Prevent());
     }
    
 }
 IEnumerator Prevent()
 {
     hasPassed = true;
     yield return new WaitForSeconds(1f);
     hasPassed = false;
 }

if you want to customize how fast it goes add this

 public float time = 1f;

and change yield return new WaitForSeconds(1f);with

 yield return new WaitForSeconds(time);

Yes this is a pretty messy way of doing it, but this is how i did it, and it worked.

Oh its old topic lol but okay, better late than never
How about this? I used float variables for precise calculations. And there is integer variable (if needed) to store current amount as whole numbers.

 public float desiredAmount = 20000f;
 public float currentAmount = 0f;
 public float amountPerSec = 1000f;
 
 public int curIntAmount;
 
 public void Update()
 {
   if(desiredAmount > currentAmount)
   {
      currentAmount += amountPerSec * Time.deltaTime;
      if(currentAmount > desiredAmount)
          currentAmount = desiredAmount;
      curIntAmount = (int) currentAmount;
   }
 }