Mathematics handwritten newspaper content

When Gauss was in elementary school, once after the teacher taught addition, because the teacher wanted to have a rest, he came up with a topic for students to calculate. The topic is:1+2+3+...+97+98+99+100 =?

The teacher is thinking, now the children must start class!

I used this as an excuse to go out, but Gauss stopped me! !

It turns out that Gauss has worked it out. Little friend, do you know how he did it?

Gauss told us how he worked it out: add 1 to 100, add 100 to 1, and add them to two lines, namely1+2+3+4+...+96+97.

100+99+98+97+96+.....+4+3+2+ 1= 10 1+ 10 1+ 10 1+.....+ 10 1+ 10 1 +1+ 1 * * adds up to one hundred 10 1, but the formula is repeated twice, so the answer obtained by dividing by 10 100 is equal to the fact of the learning process.