The teacher builds a Desmos activity with a four-quadrant grid and reads out the vertices of a shape one at a time, such as (3, 2), (−1, 4), (−2, −3) and (5, −1). Students plot each point on their own screen and join them up. The teacher's dashboard can overlay every student's points on one grid, so a cluster at (4, −1) instead of (−1, 4) shows at once that some students are reading y before x. The teacher pauses the class, shows the overlay without names, and students restate the rule of across first, then up or down, before plotting a second shape that looks right only when every point is correct.
This page is one of a growing set of PICRAT examples by cell, subject and grade. Page maintained by Andy Perryer.