Difference between revisions 1048455 and 1233820 on enwikiversity

[[File:Subtraction01.svg|right|thumb|180px|"5 − 2 = 3" (verbally, "five minus two equals three")]]
[[File:Verticle Sal_subtraction E_example.svg|right|thumb|180px|An example problem]]
In arithmetic, subtraction is one of the four basic binary operations; it is the inverse of addition, meaning that if we start with any number and add any number and then subtract the same number we added, we return to the number we started with. Subtraction is denoted by a minus sign in infix notation, in contrast to the use of the plus sign for addition.
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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.

[[Category:Mathematical theorems]]
[[Category:Elementary mathematics]]