I use a Casio FX115MS, because it's one of the very few models that understands and supports engineering suffixes for powers of 10. So, for example, I can directly multiply 47n by 33.1k and get an answer of 1.5557m, without having to first think about converting the natural way I write and specify components into E-9 or E+3 or whatever. Stick the calculator in Eng mode and it gives results directly in picofarads, megahertz or whatever other unit is appropriate, not just x.yyyE13 which requires thinking.
Just got my Sharp W516X. Just like yours. It has an Eng Mode which allows you to flip between I believe, Tera, Giga, Mega, Kilo, milli, micro, nano, pico, and of course the widely used...femto.
Also has an entire library of scientific constants ranging from mass of an proton, to plancks constant, to faradays constant. Also has a metric converter between certain measurements, not everything unfortunatley, but the more used ones. Like *C to F*, gallons to liters, etc.
It also converts to/from Hexdecimal, Binary and a slew of other N-bases.
The editor is really nice. If I have a rather complicated equation that I would like to solve, on my previous calculator (TI 30XII) which is about $5 cheaper than my Sharp, I would have to fudge around with a ton of parenthesis and then get those wrong and it get's aggrevating. "WriteView" editor works really well on this.
Like holy hell, every time I read the user manual, I find something else.
I have only two gripes about this calculator. One is that this new version of the Sharp 516 has a really glossy black panel.. And the keys are the same color as the front panel. If I was sharp I would have made the number keys perhaps a gray and then certain function keys a different color. Again, it is still very usable. Just sometimes it makes it tricky to find the key you want.
The other gripe is that the default answers are in simplest fractional form. There is a button called "Change" which cycles through mixed number, fraction, and decimal. However, if you change the mode to Stat it defaults to decimal. Again, not a huge problem. It's not terrible but it does take 2 button hits to get a decimal number.
Otherwise, huge amount of functionality, which is to be expected nowadays, but thumbs up to Sharp.
I really like it.
I wish I could take it apart just to look at it, but i appears Sharp has hermetically sealed the case in addition to using like 8 screws. The calculator is one of the lightest calculators I've ever used, which is why I want to take it apart. It feels...yes...a bit cheap, but it's not flexible at all. Doesn't bend or stress, so I'm intrigued a bit.
The only reason I want to take it apart is because my TI30XII was the dodgiest POS I've ever seen internally. Bodge jumper wires...and to make things more disgusting, they had made provision to use surface mount components in about 5 places, according to their foot print, but TI of course cheaped the hell out. They decided to instead of getting a 22uF ceramic 0805, to use a POS through hole electrolytic and solder it onto the pads. Same thing with two LEDs they had in there...for whatever reason...debugging perhaps? Crystal was soldered on the same way. Yuck. I didn't even want to own it after that..If you are literally producing millions of these calculators, I really don't understand how having some poor guy solder on some through hold components onto SMD pads is more economical. You buy probably in quantity 1,000,000 at a time. The price difference has to be so tiny...But perhaps the Sharp is the same way. I'm going to try to take it apart again...