Us math students have to get ourselves organized if we hope to convince teachers to change their requirements for this course. Which part has an error if any

Us.

Explanation:

The pronoun us is an objective pronoun, meaning that it can only be used as an object in a sentence. Since in the sentence above it refers to the subject math students, this means that it cannot be used there. Instead, the correct for would be its subjective counterpart we:

We math students ...