At Twitter Math Camp, I gave two presentations. One “My Favorite” on using the engineering design process in math class, and a second on 3D printing in math class. Here are my resources:
Using the Engineering Design Process in Math Class:
3D Printing in Math Class:
Growing Exponentially 
I love the idea of using the engineering process in math…such a good connection to other “worlds”. I’m very interested in the other tasks you mentioned at the end of the slide show. If you can easily share any of them I’d so appreciate it!