Hit the "+" to custom the calculation, set the X and X2 variables to a number and then hit "ADD" to add the result to the list. If you want to replace an item from the list to your variables, find its # number (# numer is the number on the left of each calculation in the list), select it and set respecively the rep.X, or the rep.X2 to 1 and then back to 0. If you want to delete a number from the list, select its # and hit "DELETE".
