The famous German scientist Gauss (1777 ~ 1855) was born in a poor family. Gauss learned to calculate by himself before he could speak. When he was three years old, he watched his father calculate his salary one night and corrected his father's calculation mistakes. This day is a depressing day for the math teacher. The students cringed when they saw the teacher's depressed face, knowing that the teacher was going to arrest these students again today and punish them.

"You calculate for me today, from 1 plus 2 plus 3 to 100. Whoever can't figure it out will be punished for not going home for lunch. " The teacher said this, picked up a novel, sat in a chair and read it without saying a word.

The children in the classroom picked up the slate and began to calculate: "1 plus 2 equals 3, 3 plus 3 equals 6, 6 plus 4 equals10 …" Some children added a number to the slate and then erased the result. After adding it, the number is getting bigger and bigger, which is difficult to calculate. Some children's little faces turned red, and some children's palms and foreheads oozed sweat.

Less than half an hour later, little Gauss picked up the slate and stepped forward. "Teacher, is this the answer?"

Without looking up, the teacher waved his thick hand and said, "Go, go back!"! Wrong. " He thought it impossible to have an answer so soon.

But Gauss stood still and put the slate in front of the teacher: "Teacher! I think this answer is correct. "

The math teacher wanted to shout, but when he saw the number written on the slate: 5050, he was surprised because he calculated it himself and got the number of 5050. How did this 8-year-old child get this value so quickly?