# Counting with your hands

Here’s a question

What’s the highest number you can count with your two hands?

Depending on what you already know, the answer can vary a lot.

To a layman, the answer is 10. (or 11 distinct possibilities)

If you flip your hands around then you can double the number to 20.

If you know abacus, the answer is 99 (or 100). The left hand counts tens, the right hand counts 1. The thumb represents 5, the fingers represent 1. An open right hand represents 9. etc.

If you know binary, the answer is 1023 (or 1024). Each finger represents a binary bit. So we have 10 bits, giving a total of 1024 distinct possibilities

Again, if you count both sides of your hands, then it’s 2048.

Thinking outside of the box a bit, the answer can also be 60, as illustrated by this video (http://youtu.be/cXVdYlxs8_M)

I felt an aha moment and I thought why not combine the last two ideas and see what interesting numbers can we count up to. After flexing my fingers for awhile, I realised that it is actually possible to count to a very large number.

Here are some of the candidates

1) Binary on one hand, count to 16 on the other. Limit: 16 * 32 * 2 = 1024

2) Binary on two hands, but counting to 4 on any finger. Limit = 4*1024. (use the thumbs do count binary if there’s no fingers)

I asked a few of my fellow interns this question, and turns out there are many variance of counting. It is really limited by one’s imagination.

I suppose if you are bored, you can come up with creative way to push this boundary up higher.