Steve Shapiro, a math teacher at Falls Church High School in Fairfax County, had a sick feeling when he saw the results of last spring’s state math tests, the Washington Post reports. At his school, where more than half the students are low-income, the passing rate on Algebra I dropped from 92 percent to 75 percent. The statewide decline was even bigger, from 94 percent to 75 percent. The reason was clear. The state school board had made the math tests harder. Geometry dropped from 91 percent to 69 percent, Algebra II from 87 percent to 74 percent. In most elementary and middle school grades, passing rates plunged about 20 percentage points…