When Gauss was 6 years old, a math teacher asked him what was the sum of1+2+3+4+5+6+7+8+9+10? As soon as the questioner's voice fell, 6-year-old Gauss immediately gave the answer. The teacher asked other children older than Gauss the same question, but could not get the answer immediately. Little gauss explained: if I follow the idea of 1+2+3+4+5 ..., the membership fee will take a long time; But I press1+10 =1,2+9= 1 1, 3+8 =1,4+7. It is said that Gauss became a famous mathematician when he grew up.