Please note, this blog entry is from a previous course. You might want to check out the current one.
The only variable button your calculator’s user-interface should present is x (so remove any others you added in Assignment 2 and you can remove your Test buttons and the UILabel which shows the value of the variables being used in the display).
Again inside your story board, delete the variable & test buttons as well as the label for the used variables. You might also want to rearrange the remaining buttons.