A book a day keeps kids on good math progress. Photo courtesy of the Pittsburgh Post-Gazette.

If you want to understand the underlying reason why 150 high school students drop out every hour, simply consider the math performance of Atlanta Public Schools’ 4th-graders on the 2005 National Assessment of Educational Progress and their likely performance as 8th graders four years later.

Back in 2005, 43 percent of Atlanta 4th-graders performed Below Basic on the math portion of the NAEP, with students averaging a scale score of  221, seven points below the average for their peers in other large cities (and 16 points below the average for all public school students nationwide). While just four percent of white 4th-graders scored Below Basic, 49 percent of black students scored Below Basic. Sixty-six percent of learning disabled students and 34 of regular classroom students also scored Below Basic.

Four years later, the students — now 8th graders — have gotten taller. Their academic performance, on the other hand, hasn’t gotten better. Fifty-four percent of 8th graders scored Below Basic on NAEP — a full 12 percentage points increase over the past four years; the average scale score of 259 was better than the scores four years ago, but it still trailed the average of 271 for their peers in other large cities and 282 for all public school students). The academic failure is even more pronounced: Eighty-four percent of learning-disabled students and 51 percent of regular classroom students scored Below Basic on the assessment.

Certainly the low quality of math instruction is a major problem for Atlanta students. So are the standards under which they are taught; back in 2005, the Thomas B. Fordham Institute complained that Georgia’s math standards placed “too much emphasis on calculator use and manipulatives throughout” (although middle-school algebra and geometry was considered grade appropriate).

But the biggest problem may be the simplest: The kids can’t read.

There has long been evidence that the stronger one’s reading comprehension, the more likely they are able to handle the rigors of math. A team led by University of Arizona researcher Carole R. Beale, for example, determined that the math performance of English Language Learners progressed as their reading proficiency increased. This is especially true as students reach latter grades, as simple math computations give way to word problems and abstract math concepts such as algebra and trigonometry. If an 8th-grader struggles to read a passage in The Hitchhiker’s Guide to the Galaxy, then  figuring out the answer to “This year, your brother Jack will be 2 years from being twice as old as your sister Jen” will be a gargantuan challenge.

This is evidently true in the case of Atlanta students. Fifty-nine percent of Atlanta 4th-graders scored Below Basic on the 2005 NAEP. Low reading proficiency may also explain why so many Atlanta students are labeled learning disabled in the first place. Poor reading skills can be mistaken for developmental delays, landing students into special ed classes where the chances of improving academically go to die.

Intensive reading remediation is probably the key solution for improving math skills in the long run. Bolstering reading instruction, especially at the early grades, is crucial. A community effort to read to kids (especially in poor neighborhoods home to dropout factories) would help too. The better a child reads, the better he will do in math. And vice versa.

The good news — if you can call it that — is that just 37 percent of Atlanta 4th-graders taking the 2009 NAEP scored Below Basic. It’s time for Atlanta Public Schools to get going on the intensive reading remediation these kids need.