I have an iPad app that lets you draw equations with your finger
Windows 7 and 8 have a "Math Input Panel" in Accessories (actually it may be named slightly differently in Windows 8, I must check at home) in which you can use your mouse to enter the mathematical symbols. And better than a screen shot it handshakes directly into Word. I must check on my newly acquired Surface how it works with a finger input.
These have huge erases; I just got one for my niece since she went through 10 erasers in two weeks on her Kuro Toga. BTW, the Kuro Toga Roulette is the best mechanical pencil; it's metal, and rotates the lead every time you advance. I have the gunmetal version; I only wish Uni would make it in 0.3mm.
Most of the time, I prefer using pens, but I've been using pencils more after I got my Roulette and a Pentel GraphGear 1000. Another intesting option is Pilot's Frixion erasable pens; they actually work well, much better than the PaperMates of the late 1970's.
What are the engineering and design challenges in creating successful IoT devices? These devices are usually small, resource-constrained electronics designed to sense, collect, send, and/or interpret data. Some of the devices need to be smart enough to act upon data in real time, 24/7. Specifically the guests will discuss sensors, security, and lessons from IoT deployments.