AutoLISP provides functions for working with integers and real numbers.
In addition to performing basic and complex mathematical computations, you can use the number-handling functions to help you in your daily use of AutoCAD. If you are drawing a steel connection detail that uses a 2.5" bolt with a diameter of 0.5" and has 13 threads per inch, you could calculate the total number of threads for the bolt by multiplying 2.5 by 13. In AutoLISP, this is done with the multiplication ( * ) function. Remember, the name of a function comes before the arguments you are passing to a function.
(* 2.5 13) 32.5
The arithmetic functions that have a number argument (as opposed to num or angle, for example) return different values if you provide integers or reals as arguments. If all arguments are integers, the value returned is an integer. However, if one or all the arguments are reals, the value returned is a real.
(/ 12 5) 2 (/ 12.0 5) 2.4