As a student, I found that I remembered information a lot easier when the information was in a song. I learned the 'quadratic formula song' in one of my math classes and have not forgotten the formula since. Several of my students have also found this
song helpful (and catchy!), so I though I'd share:

The 'Quadratic Formula Song' (sung to the lyrics of 'Pop Goes the Weasel')

The quadratic formula is negative b

plus or minus the square root

of b squared minus four a c

all over 2a!

(Warning, this will get stuck in your head!)