Technology

I’ve seen many of his videos and haven’t noticed any obvious errors.

He makes mistakes every time there's Brackets with a Coefficient. He always does a(b)=axb, instead of a(b)=(axb), hence wrong every time it follows a division.

what you reference to as “1917,”

No, he calls it that, though sometimes he also tries to claim it's an article (it isn't - it was a letter) - he never refers to Lennes by name. He also ignores what it actually says, and in fact disobeys it (the rule proposed by Lennes was to do all multiplication first, and yet he proceeds to do the division first, hence wrong answer, even though he just claimed that 1917 is the current rule).

Here's a thread about Lennes' 1917 letter, including a link to an archived copy of it.

Here's where Presh Talwalker lied about 1917

Here's a thread about The Distributive Law

Here's where Presh Talwalker disobeyed The Distributive Law (one of many times) (he does 2x3 instead of (2x3), hence gets the wrong answer). What he says is the "historical" rule in "some" textbooks, is still the rule and is used in all textbooks, he just never looked in any!

Note that, as far as I can tell, he doesn't even have any Maths qualifications. He keeps saying "I studied Maths at Harvard", and yet I can find no evidence whatsoever of what qualifications he has - I suspect he dropped out, hence why he keeps saying "I studied...". In one video he even claimed his answer was right because Google said so. I'm not kidding! He's a snake oil salesman, making money from spreading disinformation on Youtube - avoid at all cost. There are many freely-available Maths textbooks on the Internet Archive if you want to find proof of the truth (some of which have been quoted in the aforementioned thread).