Once a student gets the hang of basic physical principles, they can design mini games. Photo: Anirudh SharmaIt can calculate the area of a shape, providing instant feedback on geometry homework. Photo: Anirudh SharmaThe Glassified ruler combines analog and digital experiences in a cost-effective manner. Photo: Anirudh SharmaThe ruler is a great educational equalizer—students in San Francisco and Sub-Saharan Africa can both learn the basics of geometry using nothing more than a stick with regularly spaced marks. Their design is also remarkably durable and hasn’t changed much since they were invented 3,000 years ago. Now, a new interactive tool called Glassified wants to be the standard by which all other rulers are measured.Glassified is a clear plastic ruler with an embedded, translucent OLED screen connected to a microprocessor. Students can use it to measure and scribe straight lines and with the touch of a button their drawings come to life. Sketch an angled line and a simulated digital ball will roll down it like a ramp. Place the Glassified ruler on an arbitrary shape and it will calculate and display the surface area on the ruler’s screen. Plot a polygon and a ball will appear to bounce around inside it, demonstrating the principles of Newtonian physics. Glassified transforms Platonic abstractions into interactive experiences and helps bridge the gap between dry paper exercises and engaging, but expensive labs.