I have discovered, taking a look at the Org Manual, that exists an embedded mode for Calc.

https://www.gnu.org/software/emacs/manual/html_mono/calc.html#Assignments-in-Embedded-Mode

Using "C-x * e" it solves this kind of formula with units:

> From:     Ihor Radchenko
> Subject:     Re: LIterate programming with calc (help)
> Date:     Tue, 01 Nov 2022 07:22:18 +0000

---

"Fraga, Eric" <e.fraga@ucl.ac.uk> writes:

>> I guess that the main problem is that calc is tightly integrated with
>> interactive commands. Maybe ob-calc could be extended to somehow
>> indicate the commands to be executed in addition to inputting stack
>> entries.
>>
>> Not sure if there is much interest in such feature though.
>
> Thinking out loud, what would be better, but I have no idea how feasible
> it would be, would be to have ob-calc make use of the embedded calc
> functionality and syntax, so that you could write something like this:
>
> #+begin_src calc
> a := 300 m
> b := 2 a =>
> #+end_src
>
> which would output the result of any line with => on it.

I am CCing Tom Gillespie, the maintainer of ob-calc. Maybe he has
something to say.

-- 
Ihor Radchenko // yantar92,
Org mode contributor,
Learn more about Org mode at <https://orgmode.org/>.
Support Org development at <https://liberapay.com/org-mode>,
or support my work at <https://liberapay.com/yantar92>