A new test paints a poor picture for U.S. High School students, in regards to math literacy. The Program for International Student Assessment (PISA), showed that U.S. math test scores plummeted once again. Out of 73 participating countries, the U.S. now ranks 40th.

The PISA test is held every three years, and evaluates thousands of 15-year-olds from across the globe, including nearly 6,000 U.S. students. The latest test showed U.S. students with an average score of 470. That compares to a score of 488 in 2009. The global average is 20 points above, at a score of 490.

"It's kind of depressing..." said D.C. parent Michael Truscott.

"If we're going to do better than 40th, and we do want to do better than 40th, both individually and as a nation, then it's got to become part of our culture."

The test also looked at science and reading, where U.S. students did slightly better. The U.S. was ranked 25th in science, and 24th in reading.

D.C. mother Katie White said there's an easy solution.

"Teachers need to be paid more money number one," she said.

"And then there just needs to be a big emphasis on it."

The numbers demonstrated a big disparity in the nation, as well. While six percent of the U.S. students had scores in the top range, 29 percent were at the very bottom.

"We do a pretty good job at educating the elite," said Isaac Shapiro.

"But we don't necessarily do a good job of bringing people up to basic standards."

Topping the list in all three categories was Singapore. Other top ranked countries included China, Japan, Korea, and Canada. Father Mychael Judge said it was troubling to see the U.S. lag so far behind.

"A lot of kids are just being pushed through the cracks," he said.

"And they can't really read, or add, or do the basics. And then they're just getting pushed through the cracks. And being pushed to the next teacher for the next year."

There has been some debate over the effectiveness of the debate. In an open letter to the Washington Post, Yong Zhao, a professor in educational leadership and policy studies at the University of Kansas, argued that the exam does not actually evaluate a student's job readiness or math literacy.

"We must question the quality of the PISA results," he said. "Before eagerly jumping to conclusions. Don't read too much into it."