Talk:Subtraction

message: Please explain this. It starts out as 100-11, then jumps to 90-11=79, which in no way answers 100-11=(89). I may be completely confused. Oh yeah, and please don't go into vectors, I mean this is a Subtraction page, and while that is possible, the page links to Arithmetic and Elementary School! Chrishyman 02:59, 4 April 2007 (UTC)
replies: text: Yes, this gives an algorithm by example, which is not the way to do it.  The correct way would be to give the algorithm first, then an example of how it works.  The algorithm would involve m and n digit numbers c_m...c_1 and b_n...b_1 (where n<=m perhaps) and a look-up-table that gives the answer for c-b where c is a one or two digit number >= b and b is a one digit number. InformationSpace 06:43, 19 June 2007 (UTC)
thread_title:  Algorithms for subtraction section 

message: Currently this article has nothing at all about subtraction of objects other than numbers.  Perhaps links to other things (on wikipedia) that have subtraction operators defined could be added. InformationSpace 06:45, 19 June 2007 (UTC)
thread_title:  more complex subtraction 

message: In this article, difference is described as "the restult of subtraction".  Is it actually the result of subtraction, or the positive result?  Take for example The difference of 2 and 3 = 3 - 2 = 1, then The diference of 3 and 2 = 2 - 3 = -1 or |2 - 3| = 1 ?  —Preceding unsigned comment added by 137.222.234.90 (talk) 06:37, 12 October 2007 (UTC)
replies: text: Interesting question. Does "difference between a and b" mean b - a, a - b, or |a - b|? -- memset (talk) 09:18, 20 June 2008 (UTC)

text: Many mathematical concepts are named by a word that has a different meaning in common language. This may produce an ambiguity. Usually, the context makes clear whether it is the common-language or the mathematical meaning that is used. Here, "difference as comparison" is the common-language meaning; in mathematics, the meaning of "difference" is  "result of a subtraction". This was not clearly said in the article, and I have fixed this. D.Lazard (talk) 10:01, 27 July 2018 (UTC)
thread_title: Negative Difference

message: Subtraction simply reverses movement on the line of real numbers, does it not? This is especially comprehendable when subtraction is viewed as addition (as in algebra.) Consider:
5-3=2 backward movement of |3| on the number line.
5-(-3)=8 forward movement of |3) on the number line; that is to say, the "-" immediately proceeding "5" is reversing the operation that would otherwise be done if it was only "-3": addition. Children in junior-high often say this as "minus a minus." 
What I am saying is very obvious, but subtraction defined as "reversing movement on the line of real numbers" is an all-encompassing definition that would cover both the algebraic and arithmetic understanding of subtraction. This has probably been said and proven somewhere in academia, but perhaps we could place it on Wikipedia.  —Preceding unsigned comment added by CPRdave (talk • contribs) 01:07, 26 October 2007 (UTC)
thread_title:  Unambiguous definition for subtraction needed 

message: I applaud the work of the person who took the time to carefully explain how subtraction works despite there being no one who can read this article and not subtract. :) --MQDuck 07:45, 4 March 2009 (UTC)
thread_title: Line Segments

message: Is that "citation needed" tag after the explanation of the terms minuend and subtrahend really necessary? It is surely common sense to assume that these particular words are seldom used in mathematical parlance. --T.M.M. Dowd (talk) 23:49, 1 January 2010 (UTC)
thread_title: Citation Needed

message: It would be nice if a section on the problem of precision loss in limited-precision subtraction (if numbers are subtracted that are much larger than their difference) and on common workarounds could be added. As this is probably the most important source of precision loss in real-world algorithms. -- 92.229.180.109 (talk) 13:58, 22 March 2010 (UTC)
thread_title:  Subtraction and Precision 

message: The article currently states that "some" American schools teach the borrowing method.  As far as I know it is virtually universal in American schools.  Can any-one find a citation so we can beef up the statement to reflect reality?Kdammers (talk) 03:10, 9 January 2013 (UTC)
thread_title:  borrowing 

message: "In mathematics, it is often useful to view or even define subtraction as a kind of addition, the addition of the additive inverse. We can view 7 − 3 = 4 as the sum of two terms: 7 and -3. This perspective allows us to apply to subtraction all of the familiar rules and nomenclature of addition. Subtraction is not associative or commutative—in fact, it is anticommutative and left-associative—but addition of signed numbers is both."  the first part makes the "naive" reader think that subtraction should be associative ("allows us to apply to subtraction all of the familiar rules ... of addition"), but this is followed -- with-out a "however" and only a delayed "in fact"-- by a sentence that says "Subtraction is not associative...."  This makes for unnecessarily tough reading. Kdammers (talk) 03:15, 9 January 2013 (UTC)
thread_title:  counter-intuitive 

message: The article states that "… crutches are apparently the invention of William A. Brownell who used them in a study in November 1937." This is clearly false. See ref 1, which I just added for "crutches" and the Austrian method. You can read it on google books, click on the link. This is a book published in 1916 by an American, Paul Klapper. He talks about crutches and their usage in subtraction algorithms at least 21 years before Brownell's article.
John (talk) 04:01, 24 June 2014 (UTC)
thread_title:  Brownell did not invent crutches 

message: + 300 − 40 + 2 = 262.  This begs the question.  Using this method, how is one supposed to know that 300-40=260?  It seems at least one step is missing. Kdammers (talk) 06:29, 27 November 2014 (UTC)
thread_title:  Partial method 

message: "Subtraction is anti-commutative, meaning that one can reverse the terms in a difference left-to-right, and the result is the negative of the original result. Symbolically, if a and b are any two numbers, then     a - b = b - a. "
Have I forgotten all my math or is old age dementia clouding my understanding?  Or maybe it's my vision.  This looks patently wrong to me.  The text says the value of the two differences is opposite in sign (i.e., |a-b| = |b-a|.  Right, that's clear.  But  then it continues with an example that shows to my eyes some-thing quite different, .i.e., that the differences not only have the same absolute value but the same value, which is only true for a few special cases, i.e., where a=b.  Since this part of the article seems to have been around for some time, I am loathe to change it even though I just cannot at all see how it can be correct.
E.g., let a=5 and b=2.  Then a-b=5-2=3 and b-a=2-5=-3, 3NOT=-3. Hence a-bNOT [necessarily]=b-a. Or am I blind or crazy?????
Kdammers (talk) 07:49, 27 November 2014 (UTC)
replies: text: It looks as though the example should be written "a-b = -(b-a)", to match the text. Dhtwiki (talk) 09:14, 27 November 2014 (UTC)
thread_title:  Anticommutativity 

message: A century ago, it was common to teach compound subtraction as an explicit method during arithmetic. Examples of this include taking measurements in cups, tablespoons, and teaspoons and subtract, or to take an age at death and the date of death and work out the age it birth. Efficient methods for hand calculation were taught, and there are also some subtleties: for instance, the inferred age at birth from compound subtraction depends on the order in which the subtract is done, i.e., whether the days, months, and years are subtracted first, second, or third. There are numerous (old) books and articles on the subject, plenty enough that it should be covered somewhere on Wikipedia. My question: should it be a subtopic of this page, or should it have its own page? Barryriedsmith (talk) 20:57, 13 September 2021 (UTC)
thread_title:  Should compound subtraction be on this page? Or in a separate page? 

message: Subtrahend derived from 'subtrahendus' means 'to be taken away. Minuend derived from 'minuendus' means 'to be lessed/reduced'. Minus means 'less' These are given in wikipedia and other websites. For example 10 - 3 = 7, here - 3 in words minus 3 which means less 3. It means 3 is 'to be lessed'. It means 3 is the minuend by the meaning. Considering another example a boy is expected to be taken 10 marks. But he takes 7 marks, in other words the boy took '3 marks less'. This means '3 less' to 10. It means 3 is the number 'to be lessed'. So 3 is the 'minuend' by the meaning. Here expected 10 'to be taken'. So by the meaning 10 is the 'subtrahend'. Inkartumac (talk) 09:16, 13 February 2022 (UTC)
replies: text: Where did you obtain such information? - S L A Y T H E - (talk) 13:10, 14 December 2022 (UTC)

text: You have stated the opposite of what the article says, what my mathematics dictionary (James & James) tells me, and even by your own linguistic analysis in the beginning of your post. 10 is the minuend, the number 'to be lessed/reduced', 3 is the subtrahend, the number 'to be taken away'. The result is the remainder or difference. Dhtwiki (talk) 23:31, 14 December 2022 (UTC)

text: As the article says, minuend − subtrahend = difference.  That matches the language above: the minuend 10 is reduced as the subtrahend 3 is taken away from it. Certes (talk) 00:29, 15 December 2022 (UTC)

text: No I mean the etymology. Sorry if I didn't clarify. - S L A Y T H E - (talk) 16:14, 15 December 2022 (UTC)
replies: text: "Minuendus" and "subtrahendus" are the future passive participles, or gerundive, of the Latin 3rd-conjugation verbs "minuere" and "subtrahere", respectively. Is that what you're asking? Dhtwiki (talk) 02:21, 16 December 2022 (UTC)
replies: text: The sources. - S L A Y T H E - (talk) 09:58, 16 December 2022 (UTC)
replies: text: That isn't saying much about what you're specifically looking for. According to the OED, "minuend" was first used by William Jones in his 1706 book Synopsis Palmariorum Matheseos: Or, A New Introduction to the Mathematics, which may well contain "subtrahend" for the first time (I didn't confirm that). The book also contains the first occurrance of 'π' in print, according to Jones's Wikipedia article and its references.  — Preceding unsigned comment added by Dhtwiki (talk • contribs) 03:03, 17 December 2022 (UTC)
thread_title:  Related to Subtrahend and Minuend usage 

message: An editor has identified a potential problem with the redirect :Restar and has thus listed it for discussion. This discussion will occur at Wikipedia:Redirects for discussion/Log/2022 February 15#Restar until a consensus is reached, and readers of this page are welcome to contribute to the discussion.  ~~~~User:1234qwer1234qwer4 (talk) 20:19, 15 February 2022 (UTC)
thread_title:  "Restar" listed at [[Wikipedia:Redirects for discussion|Redirects for discussion]] 

message: Are there any specific claims that need citations? At least give me 3. - S L A Y T H E - (talk) 05:52, 27 December 2022 (UTC)
replies: text: The template  that is used is not the right one, and should be replaced by templates  at the beginning ot sections ,  and . For the other sections, there are enough citations, even if many of them are not WP:reliable sources and could be tagged with . D.Lazard (talk) 10:48, 27 December 2022 (UTC)
thread_title:  What needs citations?