That's the great thing about being smart: I rarely had to cross stuff out. The most scratch marks I made were in Number Theory, when decrypting something and he would only tell us "It's 200 letters long, go!" and give us some jibberish. That stuff takes a lot of trial and error to find out the system and key and then find its INVERSE, o damn that took a while, especially when the keybit was not relatively prime to the modulo...one of them took about 3 hours just to get the inverse of the key to start decryption. Sheesh.