In most textbooks I've read and programs I've work with, differential equations are normalized (made dimensionless) before being solved with some numerical method. What is the point of this? It's seems to be a lot of work for no benefice. So, after a lot of derivations, you end up with some nice equations but you're not done. No, you have to make them dimensionless, increasing the chances of making a mistake somewhere! Then, the software users don't want to use dimensionless variables (with good reasons) so their input has to be normalized. After processing the data, the results have to be converted back to dimensional units. This is really frustating since I don't see the point at all.