Subject, Skills, and Grade Level
Arithmetic and pre-algebra; appropriate for all grades, but particularly useful for 2nd-5th.

Time & Players
It depends on how you run the story; generally, assume 30 minutes to an hour for a VERY crisp, short session.

Rules, Tools, & Assessment
This does require an MC, and a deck of cards is needed. Assessments are simple to implement, as a major mechanic requires players to perform quick equations to hit a target number.