The board not only explains what an expert is, it also shows our week's experts in math--kids who completed their MCAS math homework impeccably (If you don't know what impeccable means, look it up so you can start to become a vocabulary expert!).
It's nice to have experts around. They know enough about a subject that they can help other kids who need to catch up.
Have a question about length units? Just ask Marcus. Maybe he can explain them to you.
That is, after he gets back from VACATION!