Your hour may have 60 minutes because Sumerians counted finger joints
They tapped the three joints on each of four fingers to reach 12, then tracked five sets of 12 to reach 60.
Fall of Civilizations · 8. The Sumerians - Fall of the First CitiesHold up one hand and look at your fingers. The Sumerians may have counted the same way, and our clocks still use their base-60 system.
Each of the four fingers is divided into three sections, the small segments separated by joints and creases. Historians believe the Sumerians used a thumb to tap those sections and count. They built the first cities in southern Iraq and wrote out the first multiplication tables on clay tablets.
Tap the three segments on each of the four fingers, and you reach 12 on one hand. Then raise one finger on the other hand to remember that you have finished one set of 12. When all five fingers on the second hand are up, you have counted five sets of 12, or 60, and you start over.
That may be why their number system was based on 60, while ours is based on 10. It may have been rooted in the design of the body. We still divide an hour into 60 minutes, and a minute into 60 seconds, a split the Sumerians started.
The moon also seemed to point to 60. There are about 12 lunar cycles, or full rounds of the moon, in a year, which would have suggested to them that counting by 60s was what the gods had in mind.
The circle is another leftover of base-60 math. The 360-degree split still used for angles and directions is what is left of that system, six sets of 60 wrapped into a perfect round.
So a kitchen timer counting to 60 seconds, or a geometry class using 360 degrees, still carries a base-60 system that may have started with finger counting.
Questions people ask
Can I still count to 60 the Sumerian way?
Yes. Touch your right thumb to each joint on your four fingers, from fingertip to palm, and you will tap 12 spots. Then lift one finger on your left hand to remember one dozen, and repeat until all five left fingers are up. You will have counted 60.
Why was 60 such a useful number?
Because 60 divides cleanly in so many ways. It can be split evenly by 2, 3, 4, 5, 6, 10, 12, 15, 20, and 30, while 10 can be split evenly only by 2 and 5. That made 60 especially handy for trade, rations, building, and dividing time.
How does 360 connect to 60?
It is 60 times six, and it fits neatly with a year of roughly 12 moon cycles of about 30 days each. Once a culture thinks in 60s, a 360-part circle may be a natural step, and later astronomers and mapmakers may have kept it because it divides so well into halves, thirds, quarters, and more.