How

Zippy and George receive some party invitations in the post, but sadly there's not one for Bungle. Bungle, Zippy and George and Geoffrey sort out items they no longer need and put them in a box for their next door neighbour's jumble sale. Bungle builds a tower with building blocks, but Zippy knocks it down. Geoffrey takes the box of jumble next door and notices Bungle's party invitation was delivered there by mistake, so he has an invitation after all! Rod, Jane and Freddy sing "How Many?" Zippy, George, Bungle and Geoffrey sing "How Does A Caterpillar Grow?" Then they all play a game where they have to guess how many stepping stones Bungle needs to cross a pretend river.