Difference between revisions of "Counting"
Karl Jones (Talk | contribs) (→See also) |
Karl Jones (Talk | contribs) |
||
| Line 1: | Line 1: | ||
| − | '''Counting''' is the action of finding the number of elements of a | + | '''Counting''' is the action of finding the number of elements of a [[Set (mathematics)|set]] of objects. |
| − | == | + | == Method == |
| − | The traditional | + | The traditional method of counting consists of: |
| + | |||
| + | * Continually increasing a (mental or spoken) counter by a unit for every element of the set | ||
| + | * in some order | ||
| + | * While marking (or displacing) those elements to avoid visiting the same element more than once | ||
| + | * Until no unmarked elements are left | ||
| + | |||
| + | If the counter was set to one after the first object, the value after visiting the final object gives the desired number of elements. | ||
== Enumeration == | == Enumeration == | ||
| Line 17: | Line 24: | ||
== History == | == History == | ||
| − | There is archaeological evidence suggesting that humans have been counting for at least 50,000 years. | + | There is [[archaeological evidence]] suggesting that humans have been counting for at least 50,000 years. |
| − | Counting was primarily used by ancient cultures to keep track of social and economic data such as number of group members, prey animals, property, or debts (i.e., accountancy). | + | Counting was primarily used by ancient cultures to keep track of social and economic data such as number of group members, prey animals, property, or debts (i.e., [[accountancy]]). |
The development of counting led to the development of [[mathematical notation]], [[Numeral system|numeral systems]], and [[writing]]. | The development of counting led to the development of [[mathematical notation]], [[Numeral system|numeral systems]], and [[writing]]. | ||
Revision as of 15:39, 20 February 2016
Counting is the action of finding the number of elements of a set of objects.
Contents
Method
The traditional method of counting consists of:
- Continually increasing a (mental or spoken) counter by a unit for every element of the set
- in some order
- While marking (or displacing) those elements to avoid visiting the same element more than once
- Until no unmarked elements are left
If the counter was set to one after the first object, the value after visiting the final object gives the desired number of elements.
Enumeration
The related term enumeration refers to uniquely identifying the elements of a set by assigning a number to each element.
Counting by units other than one
Counting sometimes involves numbers other than one.
For example, when counting money, counting out change, "counting by twos" (2, 4, 6, 8, 10, 12, ...), or "counting by fives" (5, 10, 15, 20, 25, ...).
History
There is archaeological evidence suggesting that humans have been counting for at least 50,000 years.
Counting was primarily used by ancient cultures to keep track of social and economic data such as number of group members, prey animals, property, or debts (i.e., accountancy).
The development of counting led to the development of mathematical notation, numeral systems, and writing.
See also
External links
- Counting @ Wikipedia
