Here's a paper on the topic. Apparently we know that they achieved this thanks to the YBC 7289 Yale Babylonian clay tablet. According to here, 4 sexagesimal figures is equivalent to 6 decimal places.
Here's a paper on the topic. Apparently we know that they achieved this thanks to the YBC 7289 Yale Babylonian clay tablet. According to here, 4 sexagesimal figures is equivalent to 6 decimal places.