I am a fourth grade teacher. Yesterday my students asked "Why are there 60 seconds in a minute?" Which also led to 60 minutes in an hour? I have had trouble determining why the number 60? Any help would be appreciated.


Hi Andy,

The importance of 60 comes from the Babylonians used a base 60 number system as compared to our base 10 system. 60 and 6x60 = 360 were very natural numbers for them to work with. They used a 360 (6X60) day calendar as opposed to our 365 day calendar. The ancient astronomers would have noticed that it takes 365 days for the sun to move (about our fixed Earth) past the stars that appeared to be fixed to an external heavenly sphere, and return to where they started. The choice of 360 days for a year may have been a compromise between a 365 day solar year and a 354 day lunar year, (consisting of 12 months of 29.5 days each).

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