Children in Ukraine returned to school for the start of the new academic year on Friday. They are back in the classroom even as the threat of war remains.

Some students have been forced to attend new schools outside of Ukraine, while many who stayed behind returned to classrooms damaged in the fighting. Still, they remain upbeat.

One 10-year-old boy said, "It's way more fun to go to school than staying at home."

Part of the instruction takes into account the new reality. Children are learning to prepare for missile threats. One school in Kyiv had to limit the number of students based on the capacity of its bomb shelter. The situation has forced some to take classes online.

The school's principal, Nataliia Shulha, said, "I hope our children can smile and don't have to worry about the war."

More than 40 percent of Ukrainian students have to rely on online or hybrid learning. However, teachers say remote instruction cannot fully replace in-person classes. About half of them report that language and math skills have declined.

Ukrainian President Volodymyr Zelenskyy said, "We do not forget a single Ukrainian child -- a single boy, a single girl -- no matter where you are now, and no matter what your September 1st is like today."

On Friday, Zelenskyy unveiled a new app that he said can help children and their teachers navigate the learning process. However, officials at UNICEF say classrooms provide far more than a learning place, especially in times of war.