What does "three and a half" mean in English for Spanish?

In English for Spanish, "three and a half" means:

tres y media

Listen to "three and a half": (If you have an HTML5 enabled browser, you can listen to the native audio below)

This is a phrase that is used in the GamesForLanguage English for Spanish Language Game in the following scenes:

• English for Spanish 3, Level 3, Scene 12