Math anxiety, feelings of dread and fear and avoiding math, can sap the brain's limited amount of working capacity, a resource needed to compute difficult math problems, reports Mark Ashcraft, a psychologist from Las Vegas who studies the problem.

"It turns out that math anxiety occupies a person's working memory,"

Ashcraft said while easy math tasks such as addition require only a small fraction of a person's working memory, harder computations require much more.

So, worrying about how you'll perform on a math test may actually contribute to a lower test score!!