Sad news. My old Spanish 3 webpage from sophomore year of high school has finally been deleted by the Geocities/Yahoo powers that be. RIP La Clase de Español. My old AP Chem page from junior year, however, lives on.

Nifty little math trick. Here's how it works. You choose a two-digit number, which we can write as 10x+y. You add the two digits, aka x+y, and subtract that from our original number, aka 10x+y-(x+y)=9x. As you can see, all multiples of 9 up to 81 have the same symbol.