Nearly 40 percent of children in grades three through eight and about 10 percent of ninth, 10th and 11th grade students will be participating in a field test in Washington of the new national exams.
Across the nation, 24 states, representing 39 percent of K-12 students in the nation or about 3 million students at about 20,000 schools will be helping the Smarter Balanced coalition test the new exams, between March 25 and June 6.
About 180 schools in Washington are expected to participate in the exercise.
Less than a third of students across the nation will be tested, but that will be enough to help the coalition determine which test questions are working and which aren't, which questions are hard enough, but not too hard, explained Joe Willhoft, executive director of the Smarter Balanced Assessment Consortium.
"This is a test of the test, not a test of the students," he said.
The former Washington state education official - he helped run the WASL and track how students were doing - said five states are testing all of their students on the new exams: California, Idaho, Montana and South Dakota.
States will also learn something from the exercise, such as whether they have the right computer equipment and Internet bandwidth to enable everyone to take the online test, Willhoft said.
The new tests are designed to test how well students are learning the new national academic standards known as the "common core." Almost every state, including Washington, has made a commitment to adopt the common core standards for math and English language arts.
Washington teachers and their union have expressed concern about both the new education standards and the new tests, saying they need more time to get used to the new program before they are judged on how well their students are doing.
The Washington Education Association used this argument to object to plans by lawmakers to require teacher evaluations to include data from statewide student tests, since they say it will take years to implement the new curriculum and get used to the new tests.
Current Washington law says students in the class of 2019 will be expected to pass the new tests in English language arts and math to earn their diploma. The new tests will be phased in over time and will be a graduation option until then, said Kristen Jaudon, spokeswoman for the Office of the Superintendent of Public Instruction.
Washington students in the class of 2019 will also need to pass a science end-of-course exam or a yet-to-adopted new science test being developed by another national group.
Parents - and students - who want to get a closer look at what the new math and English tests will be like, can take a shorter sample test online.
They will also get to see how the online test allows students to adjust the type size or have the math test read to them, making the tests more accessible for children with special needs, but any student will be able to use the special features.
Willhoft said the high school test will determine whether a student is ready to take college math or English classes, which may not make these exams appropriate as high school graduation exams, since being ready for college is a goal of K-12 education but not yet a diploma requirement.
"If a state today in 2014 would set their high school exit bar at college readiness, they would not be able to award a high school diploma to a very large group of students," Willhoft said.