Using whole fingers for binary is more useful on a table or when trying to remember numbers. On the go, I find myself using the finger-bone counting method, wh

Using whole fingers for binary is more useful on a table or when trying to remember numbers. On the go, I find myself using the finger-bone counting method, where you use your thumb to point to each of your finger bones (3 per finger) allowing you to count 12 on a hand. This probably has a name since it's so easy. And 12 has lots of really nice factors when doing math on the go. If you point at the joints plus the tip of each finger, you have 4 positions per finger (i.e., nibbles), which can be useful for working through power-of-2 stuff.