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.
I’ve recently developed an Obsidian plugin which is designed to address exactly this use case. Obsidian Numerals gives you the power of an advanced calculator inside a math code block, complete with currencies, units, variables, and math functions. You can perform calculations alongside your notes, and see both the input and the evaluated result in Live Preview or Reader view.
Numerals is not yet in the Obsidian communities plugins list, but those interested in trying it out can install it easily via BRAT. Feedback via DM or Github issues is encouraged and welcome!