NEWPORT, WALES -- It's back-to-school time for legions of students and, for a brief time Thursday morning, President Obama and British Prime Minister David Cameron.

The leaders visited the Mount Pleasant Primary School here, a brief moment of fun before heading into weighty matters at a golf resort at the NATO summit in this city of 145,000 in southeastern Wales.

For the students, the visit was serious -- and exciting -- business. They have been taking lessons on NATO, learning about the alliance and the countries that belong to it.

The two classrooms of students, who ranged in age from nine to 11, were not shy about showing off their work to the leaders -- or asking them questions.

(Read: As summit kicks off, NATO leaders talk tough on Russia, Islamic State)

In response to one boy in an art class, Obama said he didn't think he would be president when he was the boy's age. Instead, Obama thought he'd be an architect, though we're not sure that was his real goal when Obama was heard saying he "wanted to be a professional basketball player."

Obama asked the students at the boy's table their names and inquired about their artwork.

“Is this your draft?” he asked one child. “That is very nice,” he said to another. “What’s that tower?” he asked another child.

“Are there dragons?” Obama asked, a Welsh flag with a dragon on it hanging on a wall behind him. “They’re still not flying around?” he asked the children, who all giggled.

Obama asked the children how many countries were in NATO and told them that the countries had “the pact,” and clenched his fist.

Obama then joined Cameron at another table, where they inspected more artwork.

“What else have we got?” Obama asked. One drawing was said to have sheep on it, which Cameron said are “very important to Wales.”

Obama and Cameron were greeted in another classroom of 10- and 11-year-olds who were sporting maroon sweatshirts. The children were taking part in a NATO-themed lesson given by their teacher, Lt. Rachael Broughton, 28-year-old NATO reservist from the Welsh Transport Regiment, Pembrokeshire.

"Who can tell me what NATO means?" Broughton asked the class. The hashtag #mywales, used for the summit, was on the wall.

Obama and Cameron were each read a welcome; Obama by a male student, Cameron by a female pupil.

The boy welcomed Obama to Wales and Newport, noting that he is the first American president to visit Wales and would have a chance to see its “wonderful culture and rich history.”

“If you ever visit Wales again, there will be a warm welcome for you at Mount Pleasant,”  the boy said.