During the 2018–2019 school year, expert coaches from EPFL and HEP Vaud trained teachers from ten pilot schools on how to teach computer science and computational thinking to pupils aged 4–8 years, with a strong focus on unplugged activities. In the first year, the project reported an incredible adoption rate of 97%.
If you want to learn how that was possible, read more here: https://news.epfl.ch/news/epfl-provides-over-350-local-teachers-with-compute/