- The Virtual Keypunch - Make Your Personal Punch Card (masswerk.at)
Just type your text and hit the “enter” key to get your personal punch card for free. Please mind that only the limited character-set of an original keypunch (type IBM 029) is supported. All other characters will be automatically translated to the most related character available. (Sorry, like with the original, only western/latin characters are supported.)
- Summation (Wikipedia)
In mathematics, summation is the addition of a sequence of numbers, called addends or summands; the result is their sum or total. Beside numbers, other types of values can be summed as well: functions, vectors, matrices, polynomials and, in general, elements of any type of mathematical objects on which an operation denoted “+” is defined.