A nice easy QOTD... but one of those things that is good to know in case you are trying to do math on real numbers and get an answer that looks not quite correct. I've read about people having problems with reals in their math, but thankfully have not run into any issues with it yet (knock on wood). Mind you, most of what we store is numeric, int or bigint.
The above is all just my opinion on what you should do.
As with all advice you find on a random internet forum - you shouldn't blindly follow it. Always test on a test server to see if there is negative side effects before making changes to live!
I recommend you NEVER run "random code" you found online on any system you care about UNLESS you understand and can verify the code OR you don't care if the code trashes your system.