Adding more pictures to Featured images

Hi, thank you for this great template. I understand the part about adding featured images to the home page slider by adding images to posts. but, on default, the template comes with two featured images that appear on the home page and have no text, so they dont seem to be associated to any page/post. I like it, because it acts like a images slider. how can i add more images to the slideshow ? tried changing "number of featured images" to 4, but there are still only 2... help please ? Thanks