Number 6: Count to 60 (or even 144) on your fingers

The only reason we use a decimal number system (mathematicians call this base-10) is because we have 10 fingers. But I've always thought that base-10 is a bit rubbish and the ancient Sumerians agreed with me. They preferred base-60. This was probably because they figured out a way to count to 60 on there hands.

Here's how its done:

Instead of counting out each number with a whole finger, count out segments of fingers using your thumb as a marker. That way you can count to 12 on your left hand. For example in this picture I've counted to 5.

5 using the Sumerian system

Then when you get to 12 put one finger down on the right hand. Start counting the segments of your left fingers again, then when you reach 12 put a second finger down on the right. And so on.

29 on my fingers using the Sumerian system.
5 on the left hand plus 24 on the right hand (remember each finger in the right hand counts for 12)

So each finger segment on the left counts for 1. And each finger on the right counts for 12. Which means that when all the fingers on the right hand are down you've got to 60 (5 X 12 = 60).

There's still traces of this counting system left today, just think about how we measure out time; 60 seconds in a minute, 60 minutes in a hour and hours going from 1 to 12.

P.S. I suppose the Sumerians actually missed a trick because if they counted each segment on the right hand as 12 then they could have go to 144!