Education Week recently posted an article titled, "Timed Tests and the Development of Math Anxiety."
Many people, including myself, suffer from math anxiety. I'm old, and my anxiety developed long, long, ago, but, kids should no longer be subject to math anxiety with the increased interest and research in math education over the past few decades. It seems to me that the emphasis on testing, if it raises problems with math (and other testing) anxiety, may need to be reexamined.
On the subject of math anxiety, we have Overcoming Math Anxiety by Sheila Tobias [370.15 TOB]. And for a slightly skewed look at the subject, in our children's room you'll find Math Curse by John Scieszka [JP SCI].