[jacobolus]

The ancient Mesopotamian (Sumerian/Akkadian) system was floating point. The exponent was implied rather than explicitly written though. So 1/120, 1/2, 30, and 1800 were all written the same way.

Modern 'scientific notation' is also floating point.

[kps]

For a century up to the 1970s most engineering calculations were done to three decimal digits with implied-exponent floating point hardware¹.

¹ https://en.wikipedia.org/wiki/Slide_rule

[kutkloon7]

Ahh, that explains a lot. Thanks.