Here are pictures of my hallway bulletin board. It's interactive and dynamic. It's also a little more work than most bulletin boards, which typically get installed and then forgotten until they're stale. But after the initial printing of questions and setup, it only takes a couple of minutes of daily maintenance.
At Maloney all teachers are responsible for a hall bulletin board or display case space for two consecutive months. My beginning-of-year bulletin board is on August/September (and then October) in History and Current Events. I look for events that I think students in Grades 3, 4, and 5 would find interesting and write questions for them, as shown.
There are pencils taped to yarn which is suspended from the top of the frame, so students don't need to have a pencil with them to answer. I monitor the board every day and award a pencil to each student who first solves a problem correctly. I replace pages as the problems are solved.
The Math is not rocket science -- this is not instruction, with a few exceptions. Most questions are assigned to specific grades to leave easier problems for younger students. The cost of the pencils is not great -- pencils by the gross are pretty cheap. And it's rare to have a pencil disappear.
There are variations...the Current Events section always gets read. Sports can be the focus for lots of questions if your students are fans. I like wordplay and I think reading punny license plates is great reading and brain twister exercise. And sometimes I include a page that clarifies a math process -- for instance, measurement conversions, which students often get backwards at the start of school.
I illustrate each event with one or two images that I find on the Internet, an allowable practice under the Classroom Exemption, since these are displayed only and not copied and handed out to students.