To inflate with air, gently insert a plastic drinking straw through the round hole in the neck of the balloon so it extends into the main body of the balloon, and blow into the straw to inflate. When fully inflated, pull out the straw and the balloons neck will automatically seal. To deflate for future re-use, gently reinsert the straw as before (to its full length) and allow the balloon to deflate.
The Leap Frog Friends party supplies come in a variety of items. See the links at the bottom of this page for the coordinating partyware.