I'm thinking of doing an experiment with a JS program to utilize Japanese Multiplication, and I want to ask whether or not a software math shortcut is actually a shortcut at all.

To be clear, I'm contemplating writing a program to get benchmarks for the comparison of normal multiplication and Japanese Multiplication via programming, and I'd like to ask whether or not this makes sense to do before spending time to build the experiment.

Remember, this is a question of whether or not this question is appropriate for this site. Any additional thoughts on the topic should be described either in the comments or answers to the actual question.

I've also asked whether or not this question would be appropriate on Stack Overflow, Mathematics SE, and Computer Science SE:

Theoretically, the question would look like this:

Japanese Multiplication simulation - is a program actually capable of improving calculation speed? Or am I doomed from the start?

On SuperUser, I asked a (possibly silly) question about processors using mathematical shortcuts and would like to have a look at the possibility at the software application of that concept.

I'd like to write a JS simulation of Japanese Multiplication to get benchmarks on large calculations utilizing the shortcut vs traditional CPU multiplication. I'm curious as to whether it makes sense to do this.

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My Question: I'd like to know whether or not a software math shortcut, as described above is actually a shortcut at all.

This is a question of programming concept. By utilizing the simulation of Japanese Multiplication, is my program actually capable of improving calculation speed? Or am I doomed from the start?

My theory is that since addition is computed faster than multiplication, a simulation of Japanese multiplication may actually allow a program to multiply (large) numbers faster than the CPU arithmetic unit can. I think this would be a very interesting finding, if it proves to be true.

  • 1
    Based on the up-votes and no negative comments, I'm going to assume this is on-topic here and post it.
    – user129679
    May 18, 2014 at 9:24

1 Answer 1


Just to give you an official answer, conceptual questions about algorithms such as this one are on-topic for the site.

  • Actually it was closed as off topic programmers.stackexchange.com/questions/240404/…
    – user129679
    May 18, 2014 at 20:18
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    It was closed because you posted the same question across more than one site on the network without asking for migration.
    – user28988
    May 18, 2014 at 20:28
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    Not off topic. Something different (which I wasn't aware of, nor have I seen any documentation prohibiting)
    – user129679
    May 18, 2014 at 20:29
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    Perhaps the moderator who decided to incorrectly close it as off-topic due to the cross-post should supply the official SE documentation prohibiting cross-posting (if it exists, which I slightly doubt), and ask me to remove one of the posts.
    – user129679
    May 18, 2014 at 20:31
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    @jt0dd, the policy prohibiting cross-posting on multiple SE sites most certainly does exist. Search on meta.stackexchange.com. The moderator responded 100% appropriately by closing the cross-posted posts; there was nothing improper in the moderator's action to do so. Treat this as a learning experience, and accept what others are telling you about StackExchange policies.
    – D.W.
    May 19, 2014 at 5:54
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    @D.W. "off topic" is not right. Close may be right, but "off topic" is still incorrect, since the question is in no way off topic. Also this "policy" isn't policy at all but rather a popular post on the matter, where the most accepted answer is pretty.. well.. unconventional. (see the answer's top comments)
    – user129679
    May 19, 2014 at 6:35
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    the policy prohibiting cross-posting on multiple SE sites most certainly does exist show me. And if you're referring to the community meta post, where does the 'policy' (accepted answer) state in any way that one of the posts should be closed as off-topic. @D.W.
    – user129679
    May 19, 2014 at 6:38
  • @jt0dd see the policy here: "Cross-posting is strictly frowned upon..."
    – gnat
    May 19, 2014 at 8:35
  • @jt0dd see also this (declined) feature request at MSE: Shouldn't “off-topic” be only about… off-topic?
    – gnat
    May 19, 2014 at 10:46
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    @gnat the most up-voted answer on that requests suggests that off-topic be ditched completely, replaced by actual close reasons. I still see no evidence of there being any writing, anywhere on SE, that a cross post should be closed as "off-topic" - It's simply not correct. The post is not off topic in any way. That's not the proper way to handle a cross post, and none of the posts on the subject suggest it, at all.
    – user129679
    May 19, 2014 at 18:01
  • @jt0dd you need to learn more what status-declined tag means - at the question linked it is conveniently marked red to denote its special status. Applied to your case, it means that Stack Exchange team has considered complaints like your and decided to ignore these (yes, despite them being highly upvoted). This, in turn, means that at least until tag changes, one have to learn to live with this decision
    – gnat
    May 19, 2014 at 18:13
  • meta.stackexchange.com/questions/231885/… - the moderator who chose to put the question on hold as off topic was wrong to do so
    – user129679
    May 19, 2014 at 19:21
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    @jt0dd I posted a question here where we can get a broader community consenus for our site on if we should change how we choose to deal with cross-posting from now on. Depending on the answers I get here we might change our policies on this going forward and reopen your question.
    – maple_shaft Mod
    May 19, 2014 at 20:08
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    @maple_shaft I appreciate the open mind. I want things to make sense. When they don't, I do what I can to fix it. SE hasn't yet made it possible in this case.
    – user129679
    May 19, 2014 at 20:10
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    @jt0dd I agree and I am frustrated too that I don't have better guidance or moderator tools to deal with such situations. Hopefully we can get this resolved democratically. I really do like your question, and I don't want you to take it personally.
    – maple_shaft Mod
    May 19, 2014 at 20:21

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