counting on two hands

Had a fun time last night teaching my son about non-base 10 counting. After he learned that counting past 10 on your fingers requires some form of external memory (you know, some reminder that you've counted this many 10s before you start over on the fingers), he figured out that we could count base 5 (he meant 6) and use two hands. Neat idea.

We played this one out a little bit. Your right hand represents the 1s place, and your left hand the 6s place. Once you've exhausted the five fingers on your right hand, count one finger on the left and go back to a fist on the right. Keep going, and you can count up to 35 on two hands.

So then we took it to binary. Each finger is a bit and they have an order, least significant on the right (your right pinky or thumb, depending on how you hold your hand), most on the left. If you're careful about it, you can count up to 1023 this way.

Night of the living geeks.

Anyway, if you find yourself with just your hands and you need to count higher than 10, try one of these methods!