jan 1, 2400 BC - The abacus invented

Description:

The abacus invented in Babylon. This is the first automatic computer.

The reasons why this event is important:

1. By the invention of the abacus, people realized it is much easy to counting by some tool than counting by there own.

2. This makes people want to invent better counting tools.

3. The abacus improved people's math skills, and the improvement of math skills led to the improvement of science.