Grandpa's words are important here - we mustn't move the digits... or in fact do anything with the digits at all. Because what he wants us to do is:
See as follows:
Initial answer (revised after OP post clarification at +4):
The two halves of this equation are equivalent if we write them as:
As the answer from @StephenTG states, the secret is to
Implementing the necessary calculations in Excel:
We can see that, as also stated in @StephenTG's answer,
Higher finite scores are possible. For example,
... and revisiting it a little later, some minor tweaks improve this:
Later, I finally got round to doing an exhaustive computer ...
I think this might be the answer you had in mind! This is I think is the most canonical of my attempts. No change in character size and only using basic arithmetic without repeating or "abusing" operations
Here is one which makes use of powers and some "abuse" of operations.
Here we get a little more abstract. Summing from 1 to 1, i.e. ...
This is also (one would hope) not the intended answer, but I'll go with the garbagious
That would be because to my eye white can only win by
after which there are a lot of transformers, as
The sequence seems forced: white wins this way, and any deviation from black leads to being down a queen.
After this, the white king will step to b2, confining the ...