Magic Squares have been around a while. It just takes me a while to find good things. For me, I just used them for the first time in my class today. Wow. They are awesome. There is so much algebra in them.
A magic square is where you can add the columns and rows as well as the diagonals to be the same number.
First, I gave the magic square problem with pieces missing. Which by the way was excellent for my introduction to algebra students. They had to do a ton of integer addition.
Then, the students who figured it out quickly, I challenged them to figure out the algebra of the square by placing an X in the middle square and branching off from there.
If students needed more challenges, I asked them to used this template and make a new magic square with their own numbers starting with X.
For me the next step is to ask what else can I use magic squares with? Polynomial addition? Fractions? What do you think?