Thanks @x16wda @flamerz

OpalCalc looks nice, requires .net 3.5, the most smaller and featured .net notepad calculator at moment.
OpalCalc although is "small, 1mb~ requires .net 3.5 and uses 18mb~ ram

However CalcTape have a "modern" interface which it doesn't look bad at all, and I don't see any .net as requirement.
indeed CalcTape installed is 29mb~
but are: CalcTape.exe 9.8mb~ and 20mb~ in dll wich are just translations, you can eliminate those you don't want.
CalcTape uses 4.5mb~ ram
so CalcTape have nice features, translations, without .net requirements and uses less ram.

is winning CalcTape :)

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 :P

Links:
SpeQ Mathematics: https://www.speqmath.com/
TekaGen CalcPad: https://tekagen.com/calcpad/
nekoCalc: https://nekocalc.com/notepad-calculator
Numara: https://github.com/bornova/numara-calculator
Calculor: https://www.donationcoder.com/forum/index.php?topic=43180.0