This is not a simple thing, there is a lot involved in creating a UI for a calculator.
If all you want to do is calculations, you can type a calculation into the Console Window and it will execute. You can do fairly complicated calculations quickly using this technique.
Here's a video that explains how it's done:
If you want an actual popup adding machine type calculator. I've build a tool that does this and it's available on this membership site.
It's listed under the name Paper Tape Calculator (towards the bottom of the page), because it keeps a list of all the numbers and lets you paste them onto a PDF. It also automatically pulls in any numbers on a PDF Page that have a rectangle drawn around them. Writing such a tool is an advanced scripting task.
Just download this one and use it, it's free : https://www.abracadabrapdf.net/pdf-de-demo/formulaires/calculease/
I use to place it as an attchment inside a form, with a button or something useful to launch it.