Globally, “We use mathematics every day. For weather forecast, to know what time it is, to manage money. Mathematics is much more than formulas or equations, it is logic, it is rationale, it is using one’s mind to solve the biggest mysteries in the world”.

This is the opening of the American series Numb3rs, played on CBS between 2005 and 2010, with the idea that mathematics could deal with the most difficult police plots. To follow this assumption, let’s say that a lot of our everyday gestures need calculation: count money or lambs for sleeping, estimate the duration of a trip, evaluate the discount obtained on clothes on sale, cut a cake in equal slices...

Since ages, facing the increasing complexity of its needs, humankind has improved its computing resources because calculation is helpful.

The Ishango bone, a form of tally stick, is believed to be the oldest mathematical tool ever unearthed. It was found in an archaeological dig in the former Belgian Congo (now the Democratic Republic of Congo), dates back some 20,000 years and has several columns of tally marks. |

In Abyssinia (today’s Ethiopia), there was a practice of warriors placing a stone on a pile when leaving to fight, which they then picked up on their return from war. The number of stones remaining then told them how many had been lost in combat. Shepherds also counted their sheep using stones placed in a jar, at the entrance and the exit to the sheep pen. |

Natural, or manmade, stones and sticks were the origins of tablets and abacus that were used for many centuries and constantly refined for use in ever more complex calculations: lengths, time, proportions, etc. |

**The origin of “calculation”? A small Roman stone!**

With the help of Ada Lovelace, also a mathematician, he developed the “diagrams” for operating the machine. It is agreed today that Ada Lovelace has published the first algorithm for operating a machine.

The concepts of a computer, programing and program have been expressed by the British Alan Turing, in 1937. That same year, Howard Aiken presented to IBM a project of programmable calculation machine which will be developed two years later and tested in 1943. At the same time in Germany, Konrad Zuse designed a computing system able to perform an operation per second...

At the end of the war, pursuant to Turing’s concepts, John Von Neumann built the architecture used even today in most of computers. And, in the 60’s, Seymour Cray manufactured the first supercomputers for Control Data Corporation.

**TODAY, **the most powerful machines can perform several million billion operations within that same time frame!

And thus the terms HPC or supercomputing which also describe, by extension, the science that has grown up around this equipment (hardware, software, etc.).

**The supercomputer: a silicon tiger**

A supercomputer is a very big computer formed by several thousand servers all interconnected by very high-speed networks and consisting of tens of arithmetic units. Currently, a supercomputer such as Curie work as fast as a set of 100,000 laptops.

Supercomputers are useful to study the functioning and properties of a system or a phenomenonas well as to predict how it will develop, for instance how an oil platform reacts to the sea swell or fatigue in a material subject to vibrations.