Set (mathematics)

In math, a set is a collection of things.

For example, all the chairs in your house are a set. Your kitchen table is not a chair, so it is not in this set. A chair in your room is in the set.

When a thing is in a set, we say it is a member of the set.

You can list all the items in a set. That is one way to make a set. For example,

$\{apple,pear,banana\}$

Another way is to give a rule that tells which items are in a set. For example,

$\{{\text{all the counting numbers}}\}$

Sets are used in math, computers, and Physics.

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