Long division is just polynomial division with x = 10.
$SIMPLE_CONCEPT that you’re trying your best to understand is easy if you think of it as a specific example of $MORE_COMPLICATED_CONCEPT that you surely can’t understand without understanding $SIMPLE_CONCEPT
E.g.: I distinctly remember that many of the original articles about the Amplituhedron spent like a page explaining what a triangle was, then jumped straight into functions over higher-dimensional analogues without explaining any of the intermediate steps. Something-something-logarithm-of-a-simplex.
I can grok what a simplex is, but they literally just hand-waved over the bit where they take a logarithm of it in some way.
The page of explanation of what a triangle is was of zero assistance.