I've read about many mathematical miracles that can be found on The Holy Quran, but I've never actually seen a video or presentation that actually tests them. These two videos test some of the mathematical miracles in ways that you can perform yourself.
I would like to draw particular attention to the last example of the 2nd part. That one proves that addition or removal of any Ayat (verse) from The Holy Quran would hamper the code. So those who dare to say that The Quran has some Ayats that have been added by man, are proved wrong. Subhanallah.