This poster not only adds color to the classroom, but it also acts as a great reminder for students. The struggle that mathematics presents can often be frustrating for students--especially for those who don't typically like the subject. I believe that any student can be successful at mathematics as long as they persevere through the struggle.
The quote from an unknown author, "Mistakes are proof that you are trying," is an inspirational reminder that in order to be successful in the subject of mathematics, mistakes are both necessary and natural! Math isn't about the answer, but about the logical reasoning which leads to the solution.
I hope this simple quote can be used to send this positive message to students in your classroom.