ABERDEEN PROVING GROUND, Md. -- Cheers of "Hooah" reverberated on the APG Museum grounds as Maj. Gen. Nick Justice led students in the U.S. Army battle cry.

About 400 Harford County students, along with Servicemembers, veterans, military families and elected officials, gathered May 18 for Armed Forces Week.

Among the honored guests was Ralph Kelly, 89, a World War II veteran who made three combat jumps.

"I want you to give you a great big cheer to a great paratrooper here today. We are honored today to have a World War II paratrooper who has more combat jumps than most of us can even imagine," said Justice, APG's senior commander. "Today, I want you to thank him for his service with a great big Hooah."

Justice asked the crowd to remember APG's contributions while embracing its high-tech future. He shared APG's mission as the Army's new hub for science and technology with the crowd.

"Let me tell you what the rules of engagement are today, students. You are to have a great time today looking at the science, technology and engineering we do on the proving ground," Justice said. "Aberdeen Proving Ground was where the first full-logic computer was built. It is changing and transforming."

The foundation of APG is Army research and development, Justice said. He looked to the elementary- and middle-school students as the installation's leading engineers, computer scientists, chemists and physicists for the future.

"As we continue to transform, we are bringing in more science, engineering and technology jobs. That means you need to study your math," he said. "If you want to have an exciting job in the future, you should think about the language of science and engineering, which is math."

Soldiers of the 22nd Chemical Battalion, 20th Support Command (CBRNE), demonstrated examples of the technology developed at APG. They donned the Army's latest Soldier equipment, including night-vision goggles, interceptor body armor, M-4 rifles and M-40 field protective masks.

The Edgewood High School Marching Band and Chapel Hill Elementary School Choir provided music for the ceremony.

Justice concluded his remarks by asking the crowd to be good stewards of the Chesapeake Bay and its surrounding environment.

"We are home to the symbol of our country and freedom -- the American eagle. APG helped to bring the symbol of our country off the endangered species list in 2007. Why is that important' Can you imagine our country being endangered' Can you image our liberties becoming extinct' That symbol of our country is a way for us to prove that we are going to pass on those blessings of freedom to our children," Justice said.

Justice also reminded the audience of the historic Pooles Island Lighthouse relighting May 21. The lighthouse will be a beacon of the future for the region, he said.