Editing Elementary arithmetic (section)

==Successor function and ordering==
In elementary arithmetic, the [[Successor function|successor]] of a [[natural number]] (including zero) is the next natural number and is the result of adding one to that number. The predecessor of a natural number (excluding zero) is the previous natural number and is the result of subtracting one from that number. For example, the successor of zero is one, and the predecessor of eleven is ten ('''<math>0+1=1</math>''' and '''<math>11-1=10</math>'''). Every natural number has a successor, and every natural number except 0 has a predecessor.{{r|ma}}

The natural numbers have a [[Total order|total ordering]]. If one number is greater than (<math>></math>) another number, then the latter is less than (<math><</math>) the former. For example, three is less than eight (<math>3<8</math>), thus eight is greater than three (<math>8>3</math>). The natural numbers are also [[Well-order|well-ordered]], meaning that any subset of the natural numbers has a [[least element]].