After a quick search, I couldn’t find an existing plugin for Obsidian that does this, but I would love it if someone built one.
If you’re unfamiliar, Soulver and Numbr are like a simple text editor that works as a pseudo-natural language calculator. A quick look at the Numbr website will show what I mean, as that one is actually browser-based.
I think this would be super useful for Obsidian! I use these kinds of tools often for taking notes on things that use maths, like budgeting, trading, house planning, etc. and having them separate from the rest of my notes on the same topics is tiresome.