View full lesson: https://ed.ted.com/lessons/how-high-can-you-count-on-your-fingers-spoiler-much-higher-than-10-james-tanton

How high can you count on your fingers? It seems like a question with an obvious answer. After all, most of us have ten fingers -- or to be more precise, eight fingers and two thumbs. This gives us a total of ten digits on our two hands, which we use to count to ten. But is that really as high as we can go? James Tanton investigates.

Lesson by James Tanton, animation by TED-Ed.