I have to admit I am a real slacker with my bulletin boards. When I put up a display, it stays up for a while. That's why I love displays that are not seasonal. (It's a little embarrassing when you still have turkeys hanging in mid December).
For this display I had each student draw a picture of themselves in the middle of the page. They then came up with eight numbers that related to them. They could use their age, number of siblings, number of pets, month of their birthday, etc. The possibilities are endless. Using a sticky note, they covered the answer. On the sticky note, they wrote an expression that equaled the answer. This way anyone looking at the poster had to do math to figure out the answer. Hence the title "Figure Us Out!" They could check their answer by looking under the sticky note.
I did this at the beginning of the year as a get to know you/open house display. I think next year I am going to wait and do it after I teach order of operation. That way the students will be challenged to create more complex expressions
Speaking of Open House, I used this adorable idea from Crayons in the City. Each family that stopped by left with this cute treat. The thing is a had a bunch left over. So now when I am out for the day, I leave one in my sub folder. I figure it's a nice little thank you for taking care of my class while I am away. They would also be great to give to parent volunteers. You can get the labels for free here.
Be sure to head over to Forever in Fifth and check out what everyone else has to show and tell.