The decimal point is 150 years older than historians thought it was, newfound notes from 15th-century Italy reveal.
Decimal points are so simple, it seems like they should have existed forever. These handy mathematical tools break up whole numbers into tenths, hundredths and thousandths, making computation much simpler than with fractions. And some versions of decimals have been around since the 900s (in Damascus) or the 1200s (in China).
