If you like the game Portal, you’ll love learning with Teach with Portals. Materials are geared towards teachers, but parents and guardians will find this a great way to work with their learners.reference, references, online, internet, web, elementary, child, children, kid, kids, middle school, high school, teen, teens, adult, adults, young adults, young adult, novice, novices, beginner, beginners, intermediate, intermediates, Free, cheap, affordable, inexpensive