Today during my office hours, several students asked how to subtract the fraction on the right. My immediate reply, "Oh, you just use criss-cross applesauce," and I proceeded to teach them about how to use criss-cross applesauce to subtract fractions. I told them about how it's a neat trick my high school algebra teacher taught me that I still use to this day. While I thought that many people knew this trick, it seems that not even the Internet has heard of it - at least in the math sense. So, I'm going to fix that. Here is the best way to add and subtract fractions with non-matching denominators. Enjoy!
Yes, I am a nerd.
