Grid drawing method for kids

this is the tool for teaching how to draw with the grid reference.
easy to print and no more erasing reference line on photos and sketch.
watch here
https://www.youtube.com/watch?v=aWKQJJ3VCS4 this is cardboard version
and instructable guide here
https://www.instructables.com/id/Grid-Drawing-method-Screen-Using-3D-Printing-and-C/