Do you know of a classroom task that's worth sharing with the world? The Reasoning and Sense Making Task Library is a collection of classroom activities that actively encourage students to reason about and make sense of the mathematics involved in real-world tasks, and we welcome your ideas for additional tasks. Use the online form to submit your idea to the Reasoning and Sense Making Task Review Panel and, if approved, you'll be invited to develop your idea more fully for the task library.
See existing tasks at: http://www.nctm.org/rsmtasks/.
To submit a task to the reasoning and sense making library: http://www.nctm.org/standards/forms.aspx?ekfrm=33070.