At Nashville's Bailey Middle Prep, Whitney Bradley teaches her 8th-graders how to organize an essay in preparation for the writing section of Tennessee's standardized test. Most in her class trail their peers in literacy. Blake Farmer/Nashville Public Radio hide caption

itoggle caption Blake Farmer/Nashville Public Radio

As political battles rage over the Common Core, teachers like Jennifer Bahns at the University Prep Academy middle school in Detroit are trying to prepare their students for the first major Common Core exams this spring. Erin Einhorn/Hechinger Report hide caption

itoggle caption Erin Einhorn/Hechinger Report

Nancie Atwell (center) poses with former U.S. President Bill Clinton (left) and Sheikh Mohammed bin Rashid Al Maktoum, prime minister of the United Arab Emirates and ruler of Dubai, after she won the $1 million Global Teacher Prize in Dubai on Sunday. Kamran Jebreili/AP hide caption

itoggle caption Kamran Jebreili/AP

The 10 finalists for this year's Global Teacher Prize (clockwise from top left): Jacque Kahura, Stephen Ritz, Phalla Neang, Azizullah Royesh, Richard Spencer, Guy Etienne, Madenjit Singh, Naomi Volain, Kiran Bir Sethi and Nancie Atwell. Courtesy of Global Teacher Prize hide caption

itoggle caption Courtesy of Global Teacher Prize