Robotics is the best way to introduce students to STEM education. And to make sure that they enjoy it while fully understanding and retaining all the concepts is by providing hands-on STEM education. The best way to teach robotics in the classroom is by making robotics learning kits a part of the classroom.

STEMpedia provides STEM classroom kits that are specially designed for introducing students, especially beginners, to the basics of robotics along with electronics and programming in an edutaining way.

Other development boards like the Arduino and Raspberry Pi are no doubt great places to start. But these are of limited use without accessories. One will require tons of sensors, will have to invest money in purchasing shields for every other thing, deal with unnecessarily complex circuits which may not be very difficult to make for an experienced person but extremely hectic to debug for everyone, need to have a decent programming background, all of which consumes a lot of time and leads to spending a lot  while making projects.

evive, on the other hand, is an extremely power-packed and versatile prototyping platform, with features worth over $300 built-in, be it plug-and-play control for actuators, a built-in audio-visual interface, ammeter and voltmeter functions, basic oscilloscope functions, built-in BLE/ ESP/ XBee ports, etc. If one has a decent experience already, evive would be sufficient for your learning-building-debugging needs. If still a beginner, the evive Starter Kit is one of the best robotics learning kits.