How are they assigned number's in The Giver book?

They get the numbers when they are born. Let's say you and I were born in the year 2011. Let's say you were the first to be born, so you get the number one. And let's say I was born second (from another birthmother), so I got number two. They number kids to keep track of the number of children born each year. Also, when they receive their assignmnets, they sit in seats based off their numbers. So you would sit in seat one, and I would sit next to you.