I don't seem to have the words to help my second grade class understand why this method of subtraction works, so I would appreciate it if someone could help me. My biggest fear is confusing some of the students. Some of my students figured out yesterday the following. 76-28=_____ 70-20=50 8-6=2 50-2=48 I am ok with this strategy, but I am not sure how to help them understand why it works. I don't even think they have the words to explain it, but yet they are convinced it works. I challenged them to see if it always works, and they did prove it always works. Also, I don't want to come right out and tell them why it works, but rather I want to guide them as they figure it out. Thanks!!!