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I'm from Turkey and here I often see people use full stop for multiplication sign. I see them on hand written papers, on digital texts, even on printed books. This feels so weird for me (even though I live here).

hand written multiplication sign

digital one

from a book

There's an institution here called "Türk Dil Kurumu" (Turk(ish) Language Instution) that regulates the changes to Turkish, etc. Even on the page of that instution, the use of full stop (in addition to x) as the multiplication sign is promoted.

I started programming six years ago, and probably that's the reason I don't feel comfortable using full stop as multiplication. I started using * (asterisk) on digital texts, × (\times) and · (interpunct) on word processors, but never full stop. (I also use dot as the decimal seperator in contast to the country I live in).

Another thing (deviation?) to consider is that the decimal seperator is comma, not dot. This might be related to the choice of multiplication sign. If that's the case, then I'm curious what do the countries that use comma as the decimal seperator use for multiplication sign? If they also use full stop as the multiplication sign, how many countries are there? Is there a reason for it? If so, what is it? Is it just historical?

My only consolation is that some other instutions follow the international pattern (assuming the use of ×, ·, * is international; if not, it should be). One of them is ÖSYM (Student Selection and Placement System). It uses interpunct as the multiplication sign.

osym

Though, I'm not sure if the choice of interpunct here is intentional. Since foreign students also take these tests, the choice might be obligatory. Nevertheless, it's a change in the right direction.

I also saw another question about this, but I'm not satisfied with the answers, and I think mine has more depth to it. So I'm gonna post it anyway.

akinuri
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    It isn't used in formal mathematics. Only poor rendering with limited tools uses it. – egreg Sep 28 '18 at 12:51
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    "If that's the case, then I'm curious what do the countries that use comma as the decimal seperator use for multiplication sign?" Tiny answer to this: in Dutch, the decimal separator is a comma, and I rarely to never see someone use a . as a multiplication symbol. However, we use periods to separate thousands: so a number like $10^{10}$ would be rendered $10.000.000.000$. – Mees de Vries Sep 28 '18 at 12:51
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    We generally use the \cdot (latex notation) such as in $2\cdot 3$. – Wuestenfux Sep 28 '18 at 13:01
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    See Earliest Uses of Symbols of Operation : Multiplication. – Mauro ALLEGRANZA Sep 28 '18 at 13:10
  • $2x x 2x$ versus $2x\cdot 2x$ would be confusing I think. – Phil H Sep 28 '18 at 13:13
  • @egreg That's what I initially thought, but one can easily use asterisk instead of full stop. So I think it (the choice of full stop over asterisk) is deep-rooted into the culture and/or the person doesn't engage with the outside world/tranditions much to question his/her choices. – akinuri Sep 28 '18 at 13:16
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    According to Cajori (vol. 1, page 267): The dot was introduced as a symbol for multiplication by G.W. Leibniz. On July 29, 1698, he wrote in a letter to John Bernoulli: "I do not like $\times$ as a symbol for multiplication, as it is easily confounded with $x$; ... often I simply relate two quantities by an interposed dot and indicate multiplication by $ZC \cdot LM$. Hence, in designating ratio I use not one point but two points, which I use at the same time for division." – Mauro ALLEGRANZA Sep 28 '18 at 13:17
  • @MauroALLEGRANZA The page you linked is very interesting. I'll be sure to examine it further. Also does the information apply the whole world or to some specific nations? I mean could it differ from nation to nation? – akinuri Sep 28 '18 at 13:36
  • Conversely I've seen some old works that used a raised dot as a decimal point. MathWorld seems to claim that is still the norm in Britain, though I am slightly skeptical of that. – hmakholm left over Monica Sep 28 '18 at 13:40
  • Does this answer your question? Full stop as multiplication sign – callculus42 Mar 03 '21 at 18:29

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