U.S. President Barack Obama speaks during the honor ceremony of the 2013 National Teacher of the Year at the White House in Washington D.C. on April 23, 2013. (Xinhua/Fang Zhe)

U.S. President Barack Obama (2nd L) honors 2013 National Teacher Jeffrey Charbonneau (1st L) during the ceremony of the 2013 National Teacher of the Year at the White House in Washington D.C. on April 23, 2013. (Xinhua/Fang Zhe)

U.S. President Barack Obama speaks during the honor ceremony of the 2013 National Teacher of the Year at the White House in Washington D.C. on April 23, 2013. (Xinhua/Fang Zhe)

U.S. President Barack Obama speaks during the honor ceremony of the 2013 National Teacher of the Year at the White House in Washington D.C. on April 23, 2013. (Xinhua/Fang Zhe)

U.S. President Barack Obama has group photos taken with teacher representatives from all over the nation after the honor ceremony of the 2013 National Teacher of the Year at the White House in Washington D.C. on April 23, 2013. (Xinhua/Fang Zhe)