Order of operations (English Wikipedia)

Analysis of information sources in references of the Wikipedia article "Order of operations" in English language version.

Last modified: 23:28:23, 19 September 2026 (UTC)

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119doi.org

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86jstor.org

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42berkeley.edu

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32ams.org

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22microsoft.com

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21nytimes.com

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21aps.org

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11caltech.edu

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11wolfram.com

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11iso.org

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11slate.com

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11edweek.org

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11researchgate.net

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11columbia.edu

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11bell-labs.com

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11python.org

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11ruby-lang.org

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11knosof.co.uk

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11usu.edu

5,967^th place

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11mathforum.org

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ams.org (Global: 434^th place; English: 249^th place)

mathscinet.ams.org

Olver, Frank W. J.; Lozier, Daniel W.; Boisvert, Ronald F.; Clark, Charles W., eds. (2010). NIST Handbook of Mathematical Functions. National Institute of Standards and Technology. ISBN 978-0-521-19225-5. MR 2723248.
Graham, Ronald L.; Knuth, Donald E.; Patashnik, Oren (1994). Concrete Mathematics (2nd ed.). Reading, Mass: Addison-Wesley. "A Note on Notation", p. xi. ISBN 0-201-55802-5. MR 1397498. An expression of the form a/bc means the same as a/(bc). Moreover, log x/log y = (log x)/(log y) and 2n! = 2(n!).

aps.org (Global: 1,264^th place; English: 951^st place)

publish.aps.org

"Physical Review Style and Notation Guide" (PDF). American Physical Society. 2012. § IV.E.2.e. Retrieved 2012-08-05.

archive.org (Global: 6^th place; English: 6^th place)

Chrystal, George (1904) [1886]. Algebra. Vol. 1 (5th ed.). "Division", Ch. 1 §§19–26, pp. 14–20.
Chrystal's book was the canonical source in English about secondary school algebra of the turn of the 20th century, and plausibly the source for many later descriptions of the order of operations. However, while Chrystal's book initially establishes a rigid rule for evaluating expressions involving '÷' and '×' symbols, it later consistently gives implicit multiplication higher precedence than division when writing inline fractions, without ever explicitly discussing the discrepancy between formal rule and common practice.
Cajori, Florian (1928). A History of Mathematical Notations. Vol. 1. La Salle, Illinois: Open Court. §242. "Order of operations in terms containing both ÷ and ×", p. 274.
Lennes, N. J. (1917). "Discussions: Relating to the Order of Operations in Algebra". The American Mathematical Monthly. 24 (2): 93–95. doi:10.2307/2972726. JSTOR 2972726.
Ball, John A. (1978). Algorithms for RPN calculators (1st ed.). Cambridge, Mass: Wiley. p. 31. ISBN 0-471-03070-8.

bell-labs.com (Global: low place; English: low place)

Ritchie, Dennis M. (1996). "The Development of the C Language". History of Programming Languages (2 ed.). ACM Press.

berkeley.edu (Global: 621^st place; English: 429^th place)

math.berkeley.edu

Wu, Hung-Hsi (2007) [2004]. "'Order of operations' and other oddities in school mathematics" (PDF). Dept. of Mathematics, University of California. Retrieved 2007-07-03.

people.eecs.berkeley.edu

Fateman, R. J.; Caspi, E. (1999). Parsing TEX into mathematics (PDF). International Symposium on Symbolic and Algebraic Computation, Vancouver, 28–31 July 1999.

books.google.com (Global: 3^rd place; English: 3^rd place)

Swokowski, Earl William (1978). Fundamentals of Algebra and Trigonometry (4 ed.). Boston: Prindle, Weber & Schmidt. ISBN 0-87150-252-6. p. 1: The language of algebra [...] may be used as shorthand, to abbreviate and simplify long or complicated statements.
Henderson, Harry (2009) [2003]. "Operator Precedence". Henderson's Encyclopedia of Computer Science and Technology (Rev. ed.). New York: Facts on File. p. 355. ISBN 978-0-8160-6382-6. Retrieved 2023-09-17.

bos.nsw.edu.au (Global: low place; English: low place)

syllabus.bos.nsw.edu.au

"Order of operations". Syllabus.bos.nsw.edu.au. Archived from the original (DOC) on 2021-02-24. Retrieved 2019-08-02.

caltech.edu (Global: 240^th place; English: 473^rd place)

feynmanlectures.caltech.edu

For example, the third edition of Mechanics by Landau and Lifshitz contains expressions such as hP_z/2 $π$ (p. 22), and the first volume of the Feynman Lectures contains expressions such as 1/2√N (p. 6–7). In both books, these expressions are written with the convention that the solidus is evaluated last.

casio.com (Global: low place; English: low place)

support.casio.com

"Calculation Priority Sequence". support.casio.com. Casio. Retrieved 2019-08-01.

columbia.edu (Global: 554^th place; English: 368^th place)

journals.library.columbia.edu

Lee, Jae Ki; Licwinko, Susan; Taylor-Buckner, Nicole (2013). "Exploring Mathematical Reasoning of the Order of Operations: Rearranging the Procedural Component PEMDAS". Journal of Mathematics Education at Teachers College. 4 (2): 73–78. doi:10.7916/jmetc.v4i2.633. p. 73: [...] students frequently make calculation errors with expressions which have either multiplication and division or addition and subtraction next to each other. [...]

datamath.net (Global: low place; English: low place)

Announcing the TI Programmable 88! (PDF). Texas Instruments. 1982. Retrieved 2017-08-03. Now, implied multiplication is recognized by the AOS and the square root, logarithmic, and trigonometric functions can be followed by their arguments as when working with pencil and paper. (NB. The TI-88 only existed as a prototype and was never released to the public.)

doi.org (Global: 2^nd place; English: 2^nd place)

Oldham, Keith B.; Myland, Jan C.; Spanier, Jerome (2009) [1987]. An Atlas of Functions: with Equator, the Atlas Function Calculator (2nd ed.). Springer. doi:10.1007/978-0-387-48807-3. ISBN 978-0-387-48806-6.
Berger, Roger L. (2007). "Nonstandard operator precedence in Excel". Computational Statistics & Data Analysis. 51 (6): 2788–2791. doi:10.1016/j.csda.2006.09.040.
Lennes, N. J. (1917). "Discussions: Relating to the Order of Operations in Algebra". The American Mathematical Monthly. 24 (2): 93–95. doi:10.2307/2972726. JSTOR 2972726.
Ali Rahman, Ernna Sukinnah; Shahrill, Masitah; Abbas, Nor Arifahwati; Tan, Abby (2017). "Developing Students' Mathematical Skills Involving Order of Operations" (PDF). International Journal of Research in Education and Science. 3 (2): 373–382. doi:10.21890/ijres.327896 (inactive 12 Jul 2025). p. 373: The PEMDAS is an acronym or mnemonic for the order of operations that stands for Parenthesis, Exponents, Multiplication, Division, Addition and Subtraction. This acronym is widely used in the United States of America. Meanwhile, in other countries such as United Kingdom and Canada, the acronyms used are BODMAS (Brackets, Order, Division, Multiplication, Addition and Subtraction) and BIDMAS (Brackets, Indices, Division, Multiplication, Addition and Subtraction).{{cite journal}}: CS1 maint: DOI inactive as of July 2025 (link)
Knight, I. S. (1997). "Why BODMAS?". The Mathematical Gazette. 81 (492): 426–427. doi:10.2307/3619621. JSTOR 3619621.
Ameis, Jerry A. (2011). "The Truth About PEDMAS". Mathematics Teaching in the Middle School. 16 (7): 414–420. doi:10.5951/MTMS.16.7.0414. JSTOR 41183631.
Lee, Jae Ki; Licwinko, Susan; Taylor-Buckner, Nicole (2013). "Exploring Mathematical Reasoning of the Order of Operations: Rearranging the Procedural Component PEMDAS". Journal of Mathematics Education at Teachers College. 4 (2): 73–78. doi:10.7916/jmetc.v4i2.633. p. 73: [...] students frequently make calculation errors with expressions which have either multiplication and division or addition and subtraction next to each other. [...]
Dupree, Kami M. (2016). "Questioning the Order of Operations". Mathematics Teaching in the Middle School. 22 (3): 152–159. doi:10.5951/mathteacmiddscho.22.3.0152.
Taff, Jason (2017). "Rethinking the Order of Operations (or What Is the Matter with Dear Aunt Sally?)". The Mathematics Teacher. 111 (2): 126–132. doi:10.5951/mathteacher.111.2.0126.

ed.gov (Global: 318^th place; English: 138^th place)

files.eric.ed.gov

Ali Rahman, Ernna Sukinnah; Shahrill, Masitah; Abbas, Nor Arifahwati; Tan, Abby (2017). "Developing Students' Mathematical Skills Involving Order of Operations" (PDF). International Journal of Research in Education and Science. 3 (2): 373–382. doi:10.21890/ijres.327896 (inactive 12 Jul 2025). p. 373: The PEMDAS is an acronym or mnemonic for the order of operations that stands for Parenthesis, Exponents, Multiplication, Division, Addition and Subtraction. This acronym is widely used in the United States of America. Meanwhile, in other countries such as United Kingdom and Canada, the acronyms used are BODMAS (Brackets, Order, Division, Multiplication, Addition and Subtraction) and BIDMAS (Brackets, Indices, Division, Multiplication, Addition and Subtraction).{{cite journal}}: CS1 maint: DOI inactive as of July 2025 (link)

edweek.org (Global: 9,367^th place; English: 4,810^th place)

blogs.edweek.org

Ginsburg, David (1 Jan 2011). "Please Excuse My Dear Aunt Sally (PEMDAS)--Forever!". Education Week - Coach G's Teaching Tips. Retrieved 2023-09-17.

iso.org (Global: 1,190^th place; English: 1,097^th place)

In the ISO 80000 standard, the division symbol '÷' is entirely disallowed in favor of a slash symbol:
ISO 80000-2:2019, "Quantities and units – Part 2: Mathematics". International Standards Organization.

jstor.org (Global: 23^rd place; English: 15^th place)

Lennes, N. J. (1917). "Discussions: Relating to the Order of Operations in Algebra". The American Mathematical Monthly. 24 (2): 93–95. doi:10.2307/2972726. JSTOR 2972726.
Davies, Peter (1979). "BODMAS Exposed". Mathematics in School. 8 (4): 27–28. JSTOR 30213488.
Knight, I. S. (1997). "Why BODMAS?". The Mathematical Gazette. 81 (492): 426–427. doi:10.2307/3619621. JSTOR 3619621.
Foster, Colin (2008). "Higher Priorities". Mathematics in School. 37 (3): 17. JSTOR 30216129.
Ameis, Jerry A. (2011). "The Truth About PEDMAS". Mathematics Teaching in the Middle School. 16 (7): 414–420. doi:10.5951/MTMS.16.7.0414. JSTOR 41183631.
Krtolica, Predrag V.; Stanimirović, Predrag S. (1999). "On some properties of reverse Polish Notation". Filomat. 13: 157–172. JSTOR 43998756.

knosof.co.uk (Global: low place; English: low place)

Jones, Derek M. (2008) [2006]. "Developer beliefs about binary operator precedence". CVu. 18 (4): 14–21. Retrieved 2023-09-17.

masswerk.at (Global: low place; English: low place)

Backus, John Warner; et al. (1963). "§ 3.3.1: Arithmetic expressions". In Naur, Peter (ed.). Revised Report on the Algorithmic Language Algol 60 (Report). Retrieved 2023-09-17. (CACM Vol. 6 pp. 1–17; The Computer Journal, Vol. 9, p. 349; Numerische Mathematik, Vol. 4, p. 420.)

mathcentre.ac.uk (Global: low place; English: low place)

"Rules of arithmetic" (PDF). Mathcentre.ac.uk. 2009. Retrieved 2019-08-02.

mathforum.org (Global: low place; English: low place)

Peterson, Dave (22 Nov 2000). "History of the Order of Operations". The Math Forum: Ask Dr Math. Archived from the original on 2002-06-19.

microsoft.com (Global: 263^rd place; English: 259^th place)

support.microsoft.com

"Calculation operators and precedence: Excel". Microsoft Support. Microsoft. 2023. Retrieved 2023-09-17.
"Formula Returns Unexpected Positive Value". Microsoft. 15 Aug 2005. Archived from the original on 2015-04-19. Retrieved 2012-03-05.

nytimes.com (Global: 7^th place; English: 7^th place)

Strogatz, Steven (2 Aug 2019). "The Math Equation That Tried to Stump the Internet". The New York Times. Retrieved 2024-02-12. In this article, Strogatz describes the order of operations as taught in middle school. However, in a comment, he points out,
"Several commenters appear to be using a different (and more sophisticated) convention than the elementary PEMDAS convention I described in the article. In this more sophisticated convention, which is often used in algebra, implicit multiplication (also known as multiplication by juxtaposition) is given higher priority than explicit multiplication or explicit division (in which one explicitly writes operators like × * / or ÷). Under this more sophisticated convention, the implicit multiplication in 2(2 + 2) is given higher priority than the explicit division implied by the use of ÷. That’s a very reasonable convention, and I agree that the answer is 1 if we are using this sophisticated convention.
"But that convention is not universal. For example, the calculators built into Google and WolframAlpha use the less sophisticated convention that I described in the article; they make no distinction between implicit and explicit multiplication when they are asked to evaluate simple arithmetic expressions. [...]"

python.org (Global: 4,399^th place; English: 3,941^st place)

docs.python.org

"6. Expressions". Python documentation. Retrieved 2023-12-31.

researchgate.net (Global: 96^th place; English: 89^th place)

Foster, Colin (2008). "Higher Priorities". Mathematics in School. 37 (3): 17. JSTOR 30216129.

ruby-lang.org (Global: low place; English: low place)

docs.ruby-lang.org

"precedence - RDoc Documentation".

slate.com (Global: 409^th place; English: 260^th place)

Haelle, Tara (12 Mar 2013). "What Is the Answer to That Stupid Math Problem on Facebook? And why are people so riled up about it?". Slate. Retrieved 2023-09-17.

stanford.edu (Global: 194^th place; English: 182^nd place)

plato.stanford.edu

Simons, Peter Murray (2021). "Łukasiewicz's Parenthesis-Free or Polish Notation". Stanford Encyclopedia of Philosophy. Dept. of Philosophy, Stanford University. Retrieved 2022-03-26.

themathdoctors.org (Global: low place; English: low place)

Peterson, Dave (Sep–Oct 2019). The Math Doctors (blog). Order of Operations: "Why?"; "Why These Rules?"; "Subtle Distinctions"; "Fractions, Evaluating, and Simplifying"; "Implicit Multiplication?"; "Historical Caveats". Retrieved 2024-02-11.
Peterson, Dave (Aug–Sep 2023). The Math Doctors (blog). Implied Multiplication: "Not as Bad as You Think"; "Is There a Standard?"; "You Can't Prove It". Retrieved 2024-02-11.

ti.com (Global: 6,779^th place; English: 4,625^th place)

education.ti.com

"Implied Multiplication Versus Explicit Multiplication on TI Graphing Calculators". Texas Instruments. 2011. Retrieved 2025-07-22.

uga.edu (Global: 3,057^th place; English: 1,881^st place)

esploro.libs.uga.edu

Naddor, Josh (2020). Order of Operations: Please Excuse My Dear Aunt Sally as her rule is deceiving (MA thesis). University of Georgia.

unl.edu (Global: 1,697^th place; English: 926^th place)

digitalcommons.unl.edu

Vanderbeek, Greg (2007). Order of Operations and RPN (Expository paper). Master of Arts in Teaching (MAT) Exam Expository Papers. Lincoln: University of Nebraska. Paper 46. Retrieved 2020-06-14.

usu.edu (Global: 5,967^th place; English: 3,457^th place)

5010.mathed.usu.edu

Jensen, Patricia. "History and Background". 5010.mathed.usu.edu. Utah State University. Retrieved 2024-10-04.

web.archive.org (Global: 1^st place; English: 1^st place)

"Formula Returns Unexpected Positive Value". Microsoft. 15 Aug 2005. Archived from the original on 2015-04-19. Retrieved 2012-03-05.
"Order of operations". Syllabus.bos.nsw.edu.au. Archived from the original (DOC) on 2021-02-24. Retrieved 2019-08-02.
Peterson, Dave (22 Nov 2000). "History of the Order of Operations". The Math Forum: Ask Dr Math. Archived from the original on 2002-06-19.

wolfram.com (Global: 1,091^st place; English: 1,169^th place)

mathworld.wolfram.com

Weisstein, Eric Wolfgang. "Precedence". MathWorld. Retrieved 2020-08-22.

youtube.com (Global: 13^th place; English: 14^th place)

"Le calcul qui divise : 6÷2(1+2)". Micmaths (Video) (in French). 17 Nov 2020.

Order of operations (English Wikipedia)

ams.org (Global: 434th place; English: 249th place)

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caltech.edu (Global: 240th place; English: 473rd place)

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columbia.edu (Global: 554th place; English: 368th place)

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doi.org (Global: 2nd place; English: 2nd place)

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microsoft.com (Global: 263rd place; English: 259th place)

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python.org (Global: 4,399th place; English: 3,941st place)

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slate.com (Global: 409th place; English: 260th place)

stanford.edu (Global: 194th place; English: 182nd place)

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ti.com (Global: 6,779th place; English: 4,625th place)

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uga.edu (Global: 3,057th place; English: 1,881st place)

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unl.edu (Global: 1,697th place; English: 926th place)

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ams.org (Global: 434^th place; English: 249^th place)

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berkeley.edu (Global: 621^st place; English: 429^th place)

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caltech.edu (Global: 240^th place; English: 473^rd place)

columbia.edu (Global: 554^th place; English: 368^th place)

doi.org (Global: 2^nd place; English: 2^nd place)

ed.gov (Global: 318^th place; English: 138^th place)

edweek.org (Global: 9,367^th place; English: 4,810^th place)

iso.org (Global: 1,190^th place; English: 1,097^th place)

jstor.org (Global: 23^rd place; English: 15^th place)

microsoft.com (Global: 263^rd place; English: 259^th place)

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python.org (Global: 4,399^th place; English: 3,941^st place)

researchgate.net (Global: 96^th place; English: 89^th place)

slate.com (Global: 409^th place; English: 260^th place)

stanford.edu (Global: 194^th place; English: 182^nd place)

ti.com (Global: 6,779^th place; English: 4,625^th place)

uga.edu (Global: 3,057^th place; English: 1,881^st place)

unl.edu (Global: 1,697^th place; English: 926^th place)

usu.edu (Global: 5,967^th place; English: 3,457^th place)

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