Most likely, the content that is viewable in the main content section of your homepage are dynamic content items that you've checked off to publish to the 'FrontPage'. 

The FrontPage Component is what decides exactly how this looks, how many items to show there, whether you show the whole item or just the introductory text, etc. And here is how you access and administer the FrontPage Component:

1. Menu > Main Menu > Home 
(Notice, before you click on 'Home', that in the Type column it's described as 'Component - FrontPage') 
This is where you configure how many of the dynamic content items that have been published to the FrontPage will actually show up at any given time. The FrontPage Component allows for three different types of slots to display your dynamic content (remember, this is all only for dynamic content). They are Leading, Introduction, and Links. Each of these will be explained if further detail below. 

2. Everything you want to control is in the ‘Parameters’ section, on the right column. The most useful to you right now are the following:
• # Leading (The full text of these items are displayed, Intro and Body.) 
• # Intro (These are the teasers, where only the intro section of each item is displayed on your FrontPage. This is all of what you're showing now.) 
• Columns (Pretty self-explanatory. You could break this up into multiple columns, if you chose.)
• # Links (Only the title of item will show, and it will link directly to the full item. These linkable titles would appear under a “More” heading.) 

3. Any dynamic content item can be published to your FrontPage. You can see and reorder items that are published to your FrontPage here:
Content > Frontpage Manager 
This is where you can reorder them to determine which item falls in which type of the slots I described above. The order (which you can manipulate in the ‘Order’ column) is what determines what ends up in the #Leading, #Intro, #Links we configured up above (first it takes items into Leading, then Intro, then Links). So, if you only allow for one Leading item, the FrontPage Component will pull item 1 into the Leading slot, and then items 2-6 will be pulled into the five Intro slots that you have, and then items 7-10 will be listed under ‘More’ as links. It will not show up unless you re-order them and move that one up, or you change the Parameters of the component to allow for more items in any one of the three different types of slots. If there are more items there than your FrontPage component configuration allows, they simply won’t show up (but they will remain published, and can be found through the menu navigation).