youcubed: Four 4s (3-4)
youcubed (Stanford University)

This is one of my favorite inquiry tasks that helps to set norms on the first day of the year.

Inside Mathematics: 9th - 12th Grade - Newcomer ELL Algebra - Graphing Quadratics
Inside Mathematics (The University of Texas at Austin, Charles A. Dana Center)

In this lesson, we are working on reasoning and multiple representations around parabolas.