Dear Wilfred:
--Thanks for the suggestion. What I am looking for is visibility. Nixies would be fine. I used them every day, when I was in the USAF. You can read them at a glance at more than working distance, and you can use them in low light conditions. I worked in an area where there were a couple of hundred O'Scopes, and they always kept it near dark; better for the eyes, they said. In my case I may want to watch a movie without reflections, pause it, and still be able to read a calculator without turning the lights off.
--So your suggestion is not too bad. With a tablet you can touch type at arm's length, you can read large numerals at a good distance, and it can be powered by an AC adapter. When the sub $100 tabs come out ... Velcro one to the wall or to the side of my full tower Whisper case, and it can serve as a calculator when not on the road or doing something else, but a nice little calculator with a lit display, hopefully large, would better suit.
--Have a look at the picture below. I have very little room, so I must use every cubic centimeter. That is a Whisper NZXT with a UPS, and a Magic Jack phone sitting on top. Double sided tape holds the calculator USB hub and internet switch to the side, plus an Acer laptop stood on end to save space, held on by 3M Nuclear Grade Duct Tape. Laptop runs the 15" monitor, Desktop runs the 32" Vizio HDTV. Both setups have wireless M&K. Bench top is made from a 30" solid core door, 2x4s, and screws, and no glue, so as to provide quick take down and transport. I plan to lift both displays up about 16" using a simple wall mounted shelf made from 1X12 pine shelving, to free up most of the 30" bench top. This bench will eventually run 8' into the corner and 8' out of the corner. I am moving my workshop so that is all I can show for now.
"I can find in my undergraduate classes, bright students who do not know that the stars rise and set at night, or even that the Sun is a star."
Carl Sagan 1934 - 1996
Best Regards
Clear Ether