"Why is she trying to teach someone how to cut their green beans?"
Because I didn't know how!!
That's why. hehheeee
1. Line up the beans at the bottom of the bag.
2. Slice through the end of the bag with the lined up beans, removing the ends.
(I forgot where I learned this, but wherever I learned it, it's taught me two lessons in one. This technique taught me something about my childhood, that I must have been an annoying child due to the fact that my mother used to sit me down at the kitchen table with a pot full of green beans and ask me to snap off the ends with my bare fingers, one by one. Surely, she must have thought that I needed a hobby).
(Sometimes we do things in adulthood that we don't really think about, but do it out of habit, or tradition or because 'Momma did it this way.' Until one day it hits you, "Why Am I Snapping Greenbeans!?")
3. Turn the bag around, and shake the beans down to the opposite sealed side of the bag.
(Here is where you see that this is such a time saver.)