I'm searching by a free windows calculator with notepad style.
My favorite one is SpeQ Mathematics, although is not more update is small, simple and works good.
However, it does not seem to work with percentages.
I can't make things as declare a variable x=10% or make a sustration as 200-10%
I wonder if SpeQ have some way to works with percentaje.
Another good one is CalPad by TekaGen.
Is small, fast and works with percent and variables.
However this requires .NET 4.8 to works, I would like find something like this but without this kinds requirements (.net, java, etc)
another good one is nekoCalc, this does all this, just in a simple website, the cons, is online, requires a web browser

Links:
SpeQ Mathematics:
https://www.speqmath.com/TekaGen CalcPad:
https://tekagen.com/calcpad/nekoCalc:
https://nekocalc.com/notepad-calculator