I went ahead and designed a board that is only 1 inch by 3/4 of an inch which I'm pretty sure will be able to fit. By making it so small, I was able to get the cost down to $3.65 for 3 boards and I had the option of free shipping. I opted for priority mail shipping to speed it up by up to 3 days. If anybody is interested in the design, it's available here.

I thought that when I connected the battery backwards to the PowerBoost 1000, I had ruined it so I ordered a new one. It turns out I just didn't wait long enough. Oh well, that can either go towards a different project or a second calculator. It's looking like it may not be until closer to the end of the month that I will have the basics completed. I'll continue working on the software parts of the project. By the time that the circuit board and parts arrive, it should be ready to assemble. Until then, I plan on cutting out a rectangle of circuit board to use as a placeholder.