Leonhard Euler wrote in 1767 a “complete guide to algebra”. It might appear strange that one of the most productive and innovative mathematicians of all time would “waste” his time with writing a textbook for school children. But Euler knew how important algebra is. Not only for school but also in research. His book (I have first scanned my German copy in 2007.I mentioned the book also prominently in a workshop on “The adventure of teaching algebra” especially in this picture. Here is a recent video I made about about “elementary algebra”: (it was also an experiment in chroma key technology and a drone distance test). Towards the end of the movie, I mention also graph arithmetic.