But research shows that timed tests actually cause the brain so much stress, it effectively blocks the working memory part of the brain- the very part needed to do math calculations. ... For the most capable students, the research confirms, stress impedes the functioning of their working memory and reduces achievement.

Why are timed tests bad?

However, timed tests also have some drawbacks, which can be really damaging: They promote and single-handedly CAUSE math anxiety. ... It's a true process happening in the brain, and it prevents students from recalling math facts in tests though they know them! Timed tests cause children to be afraid of making mistakes.

Why are timed tests good?

Some teachers use timed tests as a perfect Friday afternoon activity and allow kids to compete against their own prior times—not the times of other students. This gives all students the opportunity to come up with strategies to improve their timing without the stress of grades.