# Binary Finger Counting

You most likely have ten fingers. Perhaps a little more, or a little less. Regardless of how many fingers you have, you’re not using them efficiently for counting.

Life pro tip: count on your fingers in binary^{1} At first I wrote down
instructions for this, but then I realised my audience is probably clever enough
to work out a scheme for themselves.. Assuming you have ten fingers, you can
count to 1023 on your hands. If you have one hand occupied^{2} As a parent of
young children, that happens to me a lot., you can still count to 31 on the
free hand.

It might feel awkward at first^{3} Okay, and thanks to the design of our hands,
nine (assuming a least-significant-thumb scheme) will never be a comfortable
number to hold for a longer period of time., but once you get the muscle memory
for it, you can flick through binary numbers on your fingers surprisingly fast.
It takes me about 8 seconds to count to 31.

If you have five fingers on one hand, you can actually count in hexadecimal on it too. Holding your palm up towards you, your fingers will have 12 creases. Together with your fingertips, that’s 16 definite locations on your fingers. You can point your thumb to each of them in turn to indicate which hexadecimal digit from 0 to F that hand represents.

Of course, this only gets you up to 15 on one hand and 255 on two, but it can be useful to know sometimes too.