Minors are allowed to create Garbanzo accounts with parental verification, so yes– your students can use Garbanzo. That being said, Garbanzo lessons were not created with elementary learners in mind.
While there are certainly some lessons in Garbanzo that are a great fit for elementary learners, most lessons are written for students in grades 5-12. We make this recommendation based on the L1 literacy skills and topical background knowledge that are assumed when writing our lessons.
We look forward to expanding our elementary offerings in the future!