Ask HN: Second generation of intro to software dev for 3rd graders

I posted this last year asking for help in creating an introduction to software development for 3rd graders:

  "Next week I'm going into my daughter's classroom to teach about software engineering. I want to teach them about the magic of it."

https://news.ycombinator.com/item?id=42056775

The best suggestion was

  "I think about the PB&J demo a lot."

It was a big hit! I took a lot of the suggestions and had so much fun. I'm going to do it again for my 4th and 5th graders classes and could use some help in improving it.

A few highlights from last year:

  * I brought a serrated knife and ketchup packets. When they said put the jelly on the bread with the knife, I gripped the serrated end and pretended my fingers bled (ketchup works great as blood). 
  * I brought in vaseline AKA petroleum jelly. When they said put jelly on the bread, I contemplated aloud "Well, you said JELLY, and this says JELLY!"

I offered to give the sandwich to one lucky kid afterward, but surprisingly, no one took me up on the opportunity to eat a sandwich with peanut butter, vaseline and ketchup. Kids these days are so spoiled, 6-7!

This year I want to do it again. But, I want to add some ideas:

  * importance of teamwork: I think this differentiates good software teams from bad teams.
  * importance of good communication: I was thinking about teaching them about how important communication and planning is. Last year I had slips of paper where I asked a different scribe to write down the instructions, and then I took those, reordered them with class input and then took action. But, perhaps I can expand on that and really drill into them the value of planning and good written communication.
  * managers: I was thinking about talking about how the managers are often the best paid, because they take responsibility for all the moving pieces, and the success or failure of the project.  I expect this might be a controversial take here on HN!

Any suggestions?