(CNN) Fourth- and eighth-graders fell behind in reading and had the largest ever decline in math, according to a national educational assessment showing the devastating effect of the Covid-19 pandemic on America's children.
The alarming findings are based on the National Assessment of Educational Progress reading and math exams, often called the "Nation's Report Card" and conducted by the National Center for Education Statistics, a branch of the Education Department.
"If this is not a wake-up call for us to double down our efforts and improve education, even before it was -- before the pandemic, then I don't know what will," US Secretary of Education Miguel Cardona told CNN's Brianna Keilar during an appearance on "New Day" Monday.
He called on schools to ensure they are using funding from the Covid relief package passed in 2021 to boost student scores.
Cardona suggested widespread teacher shortages are a "symptom of decades of underinvestment" in schools and called on districts to pay teachers more competitively.
The first national assessment of student achievement in three years revealed the largest math score declines among fourth- and eighth-graders since the initial trial assessment in 1990, according to the Center's Commissioner Peggy Carr. The tests were administered between January and March.
No state or large urban district showed improvements in math, the report said. Eighth-grade math scores sank in the more than 50 states and jurisdictions participating in the assessment. The last report card was issued in 2019, before the start of the pandemic in the US, where schools were shut down and teachers turned to online learning.
"Eighth grade is that gateway to more advanced mathematical course taking," Carr told reporters before the report's release. "This is what these students are missing. They're missing these important skills that will prepare them eventually for (science, technology, engineering and math) level careers."
The average math score of 236 for the fourth grade was 5 points lower than in 2019, and 8 points below the 2019 mark of 274 for the eighth grade. The reading score of 217 for the fourth grade was down 3 points this year -- the same decline as the eighth grade score of 260 -- compared to 2019.
The discouraging results come more than a month after the national assessment released results showing math and reading scores for 9-year-olds -- typically fourth graders -- fell between 2020 and 2022 by a level not seen in decades.
The Nation's Report Card offers the first detailed look into how health crisis disruptions and virtual learning affected fourth- and eighth-graders across the country.
The report shows the pandemic affected all students but had a disproportionate impact on the most vulnerable, who fared the worst.
Scores on the eighth-grade math exams declined across most racial and ethnic groups as well as for lower, middle and high performing students. Fourth-grade math scores dropped for all racial and ethnic groups except native Hawaiian-Pacific Islanders.
The gaps between White students and Black and Hispanic students were larger in 2022 than three years ago, with greater score declines in math for Black and Hispanic students further widening those gaps.
"What we're seeing is (lower performing) students ... dropping even faster and we're also seeing students who were not showing declines -- students at the top, meaning students at the higher performing levels -- they were holding steady before the pandemic or even improving," Carr said. "Now all the students, regardless of their ability, are dropping. That is the point we need to be taking away from this report."
The math exams reflected the performance of 116,200 fourth-graders in 5,780 schools, and 111,000 eighth-graders in 5,190 schools. The reading tests were given to 108,200 fourth-graders in 5,780 schools and 111,300 eighth-graders in 5,190 schools.
The declines are only partly attributable to the dynamics of schooling during the pandemic, when schools were shuttered and later turned to a mix of online and in-person classes in some cities.
"There's nothing in this data that tells us that there is a measurable difference in the performance between states and districts based solely on how long schools were closed," Carr said.
"And let's not forget that remote learning looks very differently all across the United States. The quality -- all of the factors that were associated with implementing remote learning -- it is extremely complex."
Declines in average math and reading scores in the fourth and eighth grades spanned the country -- in the Northeast, Midwest, South and West, the report said.
"We're not surprised to see that the math scores were going to take a bigger hit," Carr said. "Math is just simply more sensitive to schooling. You really need good teachers to teach math. Reading, on the other hand, is something that parents and the community are more comfortable with helping students with."
Carr said more analysis is needed to understand the role the pandemic played in the declines, along with other factors such as teacher shortages and bullying.
"This must be a wake-up call for the country that we have to make education a priority," Beverly Perdue, former governor of North Carolina and chair of the National Assessment Governing Board which oversees the test, said in a statement.