As of August 2014, Pick Up Lines Galore and Jokes 4 Us list many math-themed pick-up lines. An example of these includes: "My love for you is like a concave up function because it is always increasing."
Other math pick-up lines include, "How can I know so many hundreds of digits of pi and not the seven digits of your phone number?" Another example is, "Since distance equals velocity times time, let's let velocity and time approach infinity because I want to go all the way with you." As well as, "I don't know if you're in my range, but I'd sure like to take you back to my domain."