Keypad
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A keypad is a set of buttons arranged in a block or "pad" which usually bear digits, symbols and usually a complete set of alphabetical letters. If it mostly contains numbers then it can also be called a numeric keypad. Keypads are found on many alphanumeric keyboards and on other devices such as calculators, push-button telephones, combination locks, and digital door locks, which require mainly numeric input.
== As a general rule, the keys on calculator-style keypads are arranged such that 123 is on the bottom row. Whereas, in a telephone keypad, either in a home or mobile phone, there will be the 123-keys at the top. A phone key-pad also has the special buttons labelled * (star) and # (octothorpe, number sign, "pound" or "hash") on either side of the zero key. Most of the keys on a telephone also bear letters which have had several auxiliary uses, such as remembering area codes or whole telephone numbers.[1]
The keypad of a calculator contains the digits 0 through 9, from bottom upwards, together with the four arithmetic operations, the decimal point and other more advanced mathematical functions.[1]
Keypads are also a feature of some combination locks. This type of lock is often used on doors, such as that found at the main entrance to some offices.
