The California Department of Education has released guidelines for math curriculum. https://www.cde.ca.gov/ci/ma/cf/ Chapter 11 starting at line 101, it had this to state about timed math testing.
A particularly damaging assessment practice to avoid is the use of timed tests to assess speed of mathematical fact retention, as such tests have been found to prompt mathematics anxiety. When anxious, the working memory—the part of the brain needed for reproducing mathematics facts—is compromised.
Meaning the California Department of Education has stated that the type of test which is timed math section of the Cogscreen AE where you only have 35 seconds to solve the problem (without telling the test taker you only have 35 seconds) is rigged to fail the test taker.
This blog https://www.mashupmath.com/blog/2016/8/16/are-timed-math-tests-harmful-to-students goes on to state
"Stanford researcher and math education expert, Jo Boaler, has shed much-needed light on the consequences of timed testing in her reports on YouCubed.org, a Stanford-funded organization that focuses on, according to their website, transforming the latest research on math learning into accessible and practical forms.
Boaler points to brain science research suggesting that speed and time pressure blocks working memory, which is where math facts are stored in the brain.
When the working memory is blocked, students become unable to retrieve what they already know.
This inability to recall information under pressure is the hallmark of math anxiety.
According to Boaler's Report on Time Pressure Blocking Working Memory:
Conservative estimates suggest that at least a third of students experience extreme stress related to timed tests, and these are not students from any particular achievement group or economic background. When we put students through this anxiety-provoking experience, they distance themselves from mathematics.
If we continue to assess mathematical understanding using timed tests, then we will continue to turn students away and perpetuate misconceptions."
In other words the Cogscreen timed math section is a self fulfilling prophecy and according to the math 1/3 is > than the bottom 15%