Commutative Property of Addition
Pronunciation: /ˈkɒm yəˌteɪ tɪv ˈprɒp ər ti ʌv əˈdɪ ʃən/ ?
The commutative property of addition states that
adding two numbers will get the same result no matter which number comes first.^{[1]} The
order in which two numbers are added does not change the result.
This is expressed by the equation: a + b = b + a.
The commutative property of addition holds for
real numbers,
complex numbers,
matrices
of real and complex numbers, and
vectors.
Figure 1  Commutative Property of Addition 

One way to remember the commutative property of addition is to use the root word, 'commute'. Commute
means to travel from one place to another, such as commuting to work. So in the commutative property
of addition, the variable 'a' commutes to where the 'b' was, and the variable 'b' commutes to where the
'a' was.

Figure 2  Representation of the commutative property of addition. 

Figure 2 is a
representation
of the commutative property of addition that uses dots. If we put three dots
followed by two dots, the result is five dots. If we put two dots followed by
three dots, we still have five dots.


Figure 3: Representation of the commutative property of addition. 

Figure 3 is a representation
of the commutative property of addition that uses the length of a line segment to
represent each number. Notice that when we put the two segments end to end, it
doesn't matter which comes first, the total size is the same. Click on the right
end points of the two lines on top and drag the points. Dragging these points changes the
diagram showing that, for any values of 'A' and 'B', this property holds true.

References
 commutative. merriamwebster.com. Encyclopedia Britannica. (Accessed: 20100104). http://www.merriamwebster.com/dictionary/commutative.
 Jones, Burton. Elementary Concepts of Mathematics, pp 3134. MacMillan and Company, 1947. (Accessed: 20100112). http://www.archive.org/stream/elementaryconcep029487mbp#page/n52/mode/1up/search/commutative.
 Bettinger, Alvin K. and Englund, John A.. Algebra and Trigonometry, pg 2. International Textbook Company, January 1963. (Accessed: 20100112). http://www.archive.org/stream/algebraandtrigon033520mbp#page/n18/mode/1up.
 Fine, Henry B., Ph. D.. NumberSystem of Algebra Treated Theoretically and Historically, 2nd edition, pg 5. D. C. Heath & Co., Boston, U.S.A., 1907. (Accessed: 20091219). http://www.archive.org/stream/thenumbersystemo17920gut/17920pdf#page/n14/mode/1up/search/commutative.
More Information
 McAdams, David. Commutative. allmathwords.org. All Math Words Encyclopedia. Life is a Story Problem LLC. 20100115. http://www.allmathwords.org/article.aspx?lang=en&id=Commutative.
Cite this article as:
Commutative Property of Addition. 20091219. All Math Words Encyclopedia. Life is a Story Problem LLC. http://www.allmathwords.org/en/c/commuteadd.html.
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20091219: Added "References" (
McAdams, David.)
20080707: Changed manipulative from Geometer's Sketchpad to GeoGebra (
McAdams, David.)
20080616: Added sets of values for which the property holds (
McAdams, David.)
20080422: Corrected math error in page title (
McAdams, David.)
20080325: Revised More Information to match current standard (
McAdams, David.)
20070712: Initial version (
McAdams, David.)