What does mathematical summation mean?

Refers to the operation of adding several numbers. Arithmetic progression's summation and geometric progression's summation have formulas.

1785, 8-year-old Gauss was in the first grade of a primary school in rural Germany.

The teachers in the school are from the city. He has a prejudice that children in rural areas are not as clever as children in cities. However, he is very strict with his children's study. He hates students who don't pay attention in class and love to make small moves. He often beats them with a whip. Children like to listen to his class because he often talks about some very interesting things.

One day, he worked out an arithmetic problem. He said, "You calculate, 1 plus 2 plus 3, until 100?" Anyone who can't figure it out is not allowed to go home for dinner. "Say that finish, he sat in a chair, with eyes patrolling the students at my desk calculus.

In less than a minute, Little Gauss stood up with a draft paper in his hand and said, "Teacher, I have worked it out ..."

Before Gauss finished, the teacher said impatiently, "No! Recalculate! "

Little gauss quickly checked it and said loudly, "yes, teacher!" " "Say that finish, he stepped down from his seat and put the draft paper in front of the teacher.

The teacher looked down and was surprised to see "5050" written on it. He couldn't believe such a complicated math problem that an 8-year-old child worked out the correct number in less than a minute. You know, it took him more than an hour and three times to get the question right. He suspected that others had asked little Gauss to work out the problem before. Just ask little Gauss, "How did you work it out?" Little gauss replied, "I didn't add them one by one in the order of 1, 2, 3." Look, teacher, the sum of two numbers with a head and a tail is the same: 1 plus 100 is1kloc-0/,2 plus 99 is1kloc-0/,and 3 plus 98 is10. ...

Little Gauss's answer surprised the teacher. Because this is the first time he knows this algorithm. He looked at little Gauss in surprise, as if he had just met the ragged bricklayer's son. Soon, the teacher specially bought a math book for Xiao Gauss, encouraged him to continue his efforts, and recommended Xiao Gauss to the education authorities for free education. Later, little Gauss became a world-famous mathematician. In memory of him, people called his calculation method "Gauss Law".