Gauss` Iphone 5.

Carl Friederich Gauss was born in 1777 and grew up to be one of the greatest mathematicians ever. As a young boy, however, he was very naughty.

One day in school, the 8-year-old Carl, being completed bored during an arithmetic lesson, was caught playing Angry Birds on his iPhone 5. Instead of the usual punishment of 100 lashes, the teacher decided to make young Carl add up all the numbers from 1 up to 100.

Carl completed this task in a few seconds, having spotted that 1 can be paired with 100 to give 101, and 2 paired with 99 to give 101, and that there are obviously 50 such pairs, so that the required sum is 50 times 101 = 5050.

Exasperated, the teacher confiscated Carl`s iPhone 5 and demanded that Carl stand in the corner for a month (or so legend has it..).