number of days is a variable that is being displayed here. You will need to define it if you haven't already. "5" is the format. I just finished the workshops myself, but (if this is workshop 2 that you are reffereing to), the "5" in your code is "a = %0.f". So, if you want "number_of days" to be displayed like the calculator in the workshop, your code would look like
PANEL* pDisplay =
{
digits(10, 10, "number_of_days %0.f", *, 1, number of days);
flags = VISIBLE;
}
Again, number_of_days must be defined as a var at the top of your code. Hope this helps.
-Deyshawn