The Center for the Study of Mathematics Curriculum invited me to give this talk last week on digital math curricula. I described how print curricula limit the experiences we can offer our math students and then I made five recommendations for designing experiences digitally:
Show, don't tell.
Introduce the task as early and concisely as possible.
Climb the entire ladder of abstraction.
Prove math works.
Any questions or criticism, please don't hold back in the comments. I also have limited availability for consultation on these kinds of projects. Drop me a line at firstname.lastname@example.org.