In Joomla!, as default are shown in a menu item 2 types of articles:

1. leading : this type  is displayed at the beginning of the page  as a full article. If you don't want to display it just set the "Leading" value to 0.
2. intro: are short articles displayed after the leading articles.

To manage the articles layout for a menu item:

1. In the backend panel -> Menus -> Menu Manager , select the propper menu,  edit the menu item.
2. Choose the menu item for witch you want to change the layout
3. In the right corner, click on Parameters (Basic). Here, you can adjust the menu item layout: # Leading, # Intro, Columns, # Links.
4. If you set:

# Leading

      # Intro

   Columns

      # Links

 

it means that you will have:

• one full article displayed at the beginning of the page

• 4 short articles distributed in 2 columns 

• 5 links at the bottom of the page