This puzzle was created to practice with operations of complex numbers--addition, subtraction, multiplication, and conjugation (denoted with an asterisk in the puzzle). Students will have to match edges of triangles together to create a larger hexagon. It's a way for both them and you to assess their understanding of those operations, as if the hexagon isn't formed, there's something wrong!
A few notes: I put this on card stock so I can use it each term; laminated paper would work well also. There are no division problems, but it works well as an introductory or review activity. If students are prone to using their 'i' button on their calculator, I make it a graphing calculator free activity to make sure they know what they're doing!