Stats for nerds
6recommend
32mentions
30people
2017–2026years
22% recommend75% neutral3% critical
Mentions per year
What Hacker News says
- I don't know what age range "grade school" is, but I remember being taught that method when I was about 7 or 8, although it didn't really "land" properly until I read the short story "The Feeling of Power" by Isaac Asimov.
What I'm surprised to see left out here (unless I missed it in the page's horrible formatting) is a mention of the way that computers multiply two integers. They use a technique I saw described in a book when I was about 11 as the "Russian Farmer Method" (or something like that, it was in English and I might have misremembered it).
In that you shift the multiplier right and multiplicand left, halving one and doubling the other. If the multiplier is odd, add the multiplicand to the total.
It's really doing the same thing as "long multiplication" like you're taught in primary school but in binary so when you add a 0 to the right for the higher order digits you're doubling, not multiplying by ten. If you write code to do it you'd shift the multiplier first then consider whether or not to add by testing the Carry flag, or "Link bit" if like the author of the book I read you're demonstrating it on a PDP8 ;-)
But let's have a worked example, picking two numbers at random 205 * 707, use the smaller as the multiplier:
If we're disregarding shifts and adds as completing in negligible time, well, this whole thing is just done with shifts and adds, and you can predict how many of them by identifying the leftmost bit set in the multiplier.205, 707 odd, add 707 to total 102, 1414 even, disregard 51, 2828 odd, add 2828 to the total 25, 5656 odd, add 5656 to the total 12, 11312 even, disregard 6, 22624 even, disregard 3, 45248 odd, add 45248 to the total 1, 90496 odd, add 90496 to the total -------------------------------------- 144935 - It's hard to explain without spoilers, but Isaac Asimov's The Feeling of Power (1958) is relevant to this concept of warfare.
- See also The Profession by Isaac Asimov [0] and his small story The Feeling of Power [1]. Both are social dramas about societies that went far down the path of ignorance.
[0] http://employees.oneonta.edu/blechmjb/JBpages/m360/Professio...
[1] https://s3.us-west-1.wasabisys.com/luminist/EB/A/Asimov%20-%...
- Your comment very much reminds me of the Isaac Asimov story "The Feeling of Power" (https://en.wikipedia.org/wiki/The_Feeling_of_Power). I think it might be worth the time read or, in my case, re-read it.
- Arguably The Nine Billion Names of God by Arthur C. Clarke. Feeling of Power by Asimov probably also fits in the vein.
I fid it interesting that Chiang ends up in so many recent short story lists. It seems as if there are fewer recent short stories that stack up well with all-time lists.
- Really? In the case of math, it provides you with the ability to add/multiply/etc. Now, maybe you don't think that being able to do fast and reasonably accurate mental or paper-based arithmetic is important in a world in which calculators are ubiquitous but rote learning does help give you that ability even if you don't understand deeper mathematical concepts.
Asimov's short story "A Feeling of Power" is a fun read by the way.
Rote learning also has a role in things like language vocabulary but in that case there are certainly differing approaches to developing language skills. My understanding is that there's a lot of memorization in things like medicine as well.
