What do you call this?

Last night, dh and I taught the children how to sew using yarn, a large, non-sharp needle, and plastic grids. I know enough about sewing to know that this isn’t embroidery or needlepoint. So what do you call this craft?

There are many different shapes of these grids at our craft store including small and large squares, stars, hexagons, hearts, even placemat size. I want to add this handicraft into my scheduler, but I don’t know what to call it. 

You can tell I’m an expert in this.

~Lindsey