No it doesn't, multiplication and division always take precedence over addition and subtraction. You'd need parentheses to clarify what is in the divisor since that can be ambiguous with line notation.
Times 5 and times 10 tables are really easy for me. So yeah, in my mind it's an easier comuptation.
That being said having a result of a little over a 1000 gives me an estimate for the magnitude of a number – it's around a thousand. It might be more or less but it's not far from there.
72 * 10 + 70 * 3 + 2 * 3
That's what I do in my head if I need an exact result. If I'm approximateing I'll probably just do something like 70 * 15 which is much easier to compute (70 * 10 + 70 * 5 = 700 + 350 = 1050).
Just looking at the provided numbers it feels marginal, how is it much better?
Biggest increase is like ~12 % on one of the benchmarks. Other benchmarks don't show any significant changes
Me, the dev: "Nobody reported this as a problem… Ok, don't care, moving on." Also, if I can't reproduce it, I can't fix it, no point in wasting time more than that.
Speaking personal experience hence extremely biased.
Books ain't worth shit by them selves. There is no better resource than experience. I learned programming and other stuff just by trying and the googling and reading up on the problem.
Books are only as good as they are searchable and can be used as a reasource to solve problems (and I'm not talking about literature in general, I love reading, just not profession related stuff).
TL; DR
I strongly disagree. Nothing tops just tinkering and figuring things out practically. My whole career is based on my ability to learn and solve IT problems and google is still the best tool for that.