Bamboo slips oldest decimal calculator, Guinness certifies

Bamboo slips more than 2,300 years old were recognized on Sunday by Guinness World Records as the world's earliest decimal calculation tool.

The 21 slips, crafted around 305 BC during the Warring States Period (475-221 BC), are each 43.5 centimeters long and 1.2 cm wide.

When arranged together as a multiplication table, the slips can perform multiplication and division of any two whole numbers under 100 and numbers with a fraction of 0.5.