It is also a chance to review a variety of math skills, counting bags of popcorn, comparing relative sizes, and, finally, counting change and dollar bills, culminating in a gradewide meeting where they figure out how many mittens their efforts will buy.
All of of this happens in full view of the school.
Math at Gordon is a very public event.
The stereotypical math student sits alone and performs calculations in silence.
In a Gordon third grade classroom, this performance has an audience.
The lesson has them writing - and solving - their own word problems, and the teacher models hers for the whole class.
Then, they solve the problem together using three different strategies.
When the students write their own word problems, they come up with scenarios that are close to their hearts.
Then, they swap their sheets, and students tackle their classmates' creations.
Finally, they swap again to correct each others' work, and each student gets to see their classmates' work alongside their own.
In a seventh grade classroom, a teacher stands at the board, going over geometry formulas.
How much paint do you need to cover a floor this big?
No one can talk through area and volume without waving their hands around.
The whiteboard demonstration transitions easily into pencil-and-paper practice.
The room does not fall silent.
The teacher makes her rounds, prodding students with questions.
Deskmates turn to each other and compare notes.
The math specialist slips into the room and circulates, as well.
The next day, the floor paint question becomes a floor plan question.
Students fan out across the school to make blueprints of the school.
Each team starts with a sketch of their room.
Then, they measure each surface and label it.
These are spaces these students know well.
Yet the teams are continually erasing and redrawing.
The Field House hallway is longer than anyone thought.
The Dining Hall panels are not all the same width.
The Commons is much more of a square than a rectangle.
Disagreements erupt, passerby stop to watch, passing adults are drawn into the conversation.
This is the sound of students who have been taught, in the words of the third grade teacher, to "justify and explain all of their decisions."
Throughout the process, they are continually refining their understanding of proportion and scale.
When these students return to their desks, they will likely sit in silence, grinding out the necessary calculations to perfect their blueprints.
They had already done the hard part - the thinking, and measuring, and arguing and explaining - together.