Imagine hearing the squeals and laughter coming from other classrooms as they have started their parties.
Imagine being a teacher, and asking her class if they would like to stay on the netbooks practicing math a bit longer, or start their party.
Then imagine the principal walking through to say hello and wondering what this SILENT class is doing?
"Oh, we're just doing math."
They decided to start the party late so they could spend a bit more time "working".
:)