There are three classes in a row.

Three rows and one company.

Plus the cooking squad and other service support soldiers.

About 100 people

One battalion, three companies.

A regiment has three battalions.

This is a group of about 900 people.

One division and three regiments.

One army and three divisions

In this way, a division has more than ten thousand people.

An army of 40,000 people is close to 50,000.