You are still not precise:

Need you arithmetic routines only,
need you some input, (keyboard),
need you some output (speaker, display),
need you a certain number format,
need you a certain precision,
need you certain functions (sinus, statistics),
etc., etc..


The first step on all projects is always, to define it concrete in absolute all points, so that another person can realize it without any further question to you and then also the result fits on every of your requirements.


Please be more precise many, many times.


Peter