Editing Addition (section)

=== Commutativity ===
[[File:AdditionComm01.svg|right|upright=0.5|thumb|4 + 2 = 2 + 4 with blocks]]
Addition is [[commutative]], meaning that one can change the order of the terms in a sum, but still get the same result. Symbolically, if <math> a </math> and <math> b </math> are any two numbers, then:{{sfnp|Musser|Peterson|Burger|2013|p=[https://books.google.com/books?id=8jh7DwAAQBAJ&pg=PA89 89]}}
<math display="block"> a + b = b + a. </math>
The fact that addition is commutative is known as the "commutative law of addition"{{sfnp|Berg|1967|p=[https://books.google.com/books?id=aGXFCUaFCW0C&pg=PA14 14]}} or "commutative property of addition".{{sfnp|Behr|Jungst|1971|p=[https://books.google.com/books?id=GJXOBQAAQBAJ&pg=PA59 59]}} Some other [[binary operation]]s are commutative too as in [[multiplication]],{{sfn|Rosen|2013|loc = See the [https://books.google.com/books?id=-oVvEAAAQBAJ&pg=SL1-PA1 Appendix I]}} but others are not as in [[subtraction]] and [[Division (mathematics)|division]].{{sfnp|Posamentier|Farber|Germain-Williams|Paris|2013|p=[https://books.google.com/books?id=VfCgAQAAQBAJ&pg=PA71 71]}}