# Mathematical Expressions

Template files can also contain mathematical expressions.

```
*nodes()
*format()
*string("node,")
*field(integer,id,10)
*string(",")
*field(real,[x+100.0],10)
*string(",")
*field(real,y,10)
*string(",")
*field(real,z,10)
*end()
*output()
```

100.0 is added to the x-coordinate of the nodes and is sent to the formatter, where it is written to the file. The square brackets, [], around the formula tell the parser that the enclosed text is a formula and not to interpret the asterisk, *, as a new command.

Addition | + |

Subtraction | - |

Multiplication | * |

Division | / |

Modulus | % |