Talk:198 (number)

Draft for number 198
Hello. I realized 198 does not have a wikipedia page yet. I knew it was a brazilian phone number, and I found some interesting mathematical properties of it after some researching. This is my first wikipedia article, and I want to submit it for review. However, I was wondering if my draft is correctly formatted according to the WikiProject guidelines. Natureader (talk) 06:53, 4 June 2023 (UTC)

Reviewer Note
I am attempting to accept the draft via a round-robin move. Robert McClenon (talk) 19:55, 5 June 2023 (UTC) - I think that I have completed the round-robin move and only left one accidental redirect and one redirect as the reslt of a race condition. Robert McClenon (talk) 20:14, 5 June 2023 (UTC)


 * What happened to the page that previously occupied the spot? That page was not just a simple redirect, the page history is required for attribution as material from it was merged into 190 (number). -- Whpq (talk) 00:27, 6 June 2023 (UTC)
 * Apparently McClenon buried its history at Draft:198 (number) (the history) after some confusing page moves. —David Eppstein (talk) 00:37, 6 June 2023 (UTC)
 * The draft of a title is a place where the history is sometimes buried. If you dig there, you may find things that should be left buried.  Robert McClenon (talk) 06:04, 6 June 2023 (UTC)

Does it matter whether it is true?
I removed this claim: "198 is the only number equal to the sum of its digits concatenated twice (198 = 11 + 99 + 88)." Never mind whether the "W-source" is "W-reliable", or who Erich Friedman is, he only claims that 198 = 11 + 99 + 88 which is True (not "W-true") by elementary arithmetic. There is no evidence for the stunningly insignificant claim that this is the only such number. Imaginatorium (talk) 06:38, 26 July 2023 (UTC)


 * Erich Friedman's GitHub is listed on the number notability guidelines as a good source (Notability (numbers)). Also, the fact that it is the only such number is easily verifiable with a pocket calculator, which the WikiProject page says doesn't need a proof (WikiProject Numbers). Any number with less than 3 digits is too small to have a chance at satisfying the property, any number with more than 3 digits is too large. You can use your calculator and simply check that 198 is the only one with such property. Natureader (talk) 02:27, 15 August 2023 (UTC)
 * The precise text from Github is: "198 = 11 + 99 + 88." This is true, and verifiable (immediately, in an obvious way) without a calculator. So the Github source is not even required. But the source does not even state the claimed property of being the only such number, and is thus of no use anyway. Verifying by exhaustive search is not really "elementary calculation", and anyway a simpler proof is easy... the claim is that for a, b, c, integers in the range [1, 9], then 100a+10b+c = 11a+11b+11c. (Though I question whether the wording in the article is really clear enough to make the meaning obvious...)


 * Rearrange both sides: 89a = b + 10c
 * Range for LHS is 89, 178, ...; range for RHS is 11..99
 * Only possible value is therefore 89, so a=1.
 * If b+10c = 89, only values are b=9, c=8. QED


 * For the claim to remain it needs valid support: either your arm-waving appeal to exhaustive search, or my four-line proof.


 * The Github article is plainly scraping the bucket, since its aim is to list "a distinctive fact" about every one of the natural numbers, and only gives up at 391. David Wells' "Dictionary of Curious and Interesting numbers" (Penguin) on the other hand gives up at 43 (if you count his entry for 39 as the "first uninteresting number". This seems to me a much better basis for deciding what might be W-notable.


 * I will remove the item again; please do not put it back without a *much* better argument. Imaginatorium (talk) 05:56, 15 August 2023 (UTC)