858
6÷2(1+2)
(programming.dev)
I would do the mighty parentheses first, and then the 2 that dares to touch the mighty parentheses, finally getting to the run-of-the-mill division. Hence the answer is One.
@wischi "Funny enough all the examples that N.J. Lennes list in his letter use implicit multiplications and thus his rule could be replaced by the strong juxtaposition".
Weird they didn't need two made-up terms to get it right 100 years ago.