First, create a child theme, because you don’t want to edit the theme files directly (if you make changes to the theme’s files, those changes will be lost the next time the theme is upgraded).
In your child theme’s function.php file, copy over the code from the the parent’s function.php file for the twentyfourteen_setup() function. Start the copy at this line (i.e., include this line):
function twentyfourteen_setup() {
and end the copy just before this line (i.e., don’t include this line):
endif; // twentyfourteen_setup
In your child theme’s copy of twentyfourteen_setup(), look for this section of code:
// Add support for featured content.
add_theme_support( 'featured-content', array(
'featured_content_filter' => 'twentyfourteen_get_featured_posts',
'max_posts' => 6,
) );
Change 6 to whatever value you want. If you’re using a Grid for featured content, I would probably use a multiple of 3 (e.g., 9, 12, 15), with a maximum value is 15. If you’re using a slider, any value up to 15 will look OK.
