Parents rallied Tuesday at Prospect Park against the Common Core math exam.

Some parents called the opt-out movement a "celebration," saying that Common Core tests are based on flawed learning standards that are unfair to students and the teachers who will be evaluated based on test results.

According to the group NYC Opt Out, about 200,000 third- through eighth-graders across New York opted out of the three-day English portion of the Common Core exam last week.

Testing for the Common Core math exam starts Wednesday, and opt-out advocates say they hope many children will also skip this exam.

One young student expressed her testing fears. "Sometimes you get really nervous before the test, and you mess up," said Maizie Schaffner. "And that's not your best work. So it's not really fair that we have to get graded on something that's not our best work."

Parents say they don't expect students to face any repercussions for opting out of the test.