Floor and Ceiling functions belongs to number functions in Tableau.
Ceiling: This function helps in rounding a decimal value to greater or equal value.
Floor: This Function in tableau helps to round an integer to is Lesser values or equal value.
Example:
Sum of sales = 2,,297,200.8603
Floor(sum(Sales))
Floor of sales = 2,297,200.000
Ceiling Function :
Ceiling(sum(Sales))
Ceiling of sales= = 2,297,201.000