9th grade Algebra students worked through a great activity called "Always Sometimes Never" where they were given algebraic statements and asked to evaluate their 'Truthness'. Amazing California math teacher Fawn Nguyen introduced me to Always Sometimes Never through this blog post and Mr. Olivares adapted this activity to meet the needs of his students.
My 45 minute stay in the classroom absolutely flew by as all kids were engaged in high level thought and questioning, and several students discovered some misconceptions they had about variables and expressions.