Finger Systems

Finger systems --- Signing --- Days in a month --- Chisenbop --- Multiplication --- Up to 100,000

This is really nothing to do with numbers, but it is useful. Some moths have 30 days, some months have 31 and February is awkward. There is a poemwhich starts "Thirty days has September..." but if, like me, you can't remember the second line, try this instead.

Days in months

Hold your fists next door to each other, knuckles upwards. Label the knuckles and gaps between the knuckles with the months. You don't use the thumb knuckle (which is lower down your hand anyway). You have a knuckle left over, so ignore it. Now, all the knuckle months have 31 days, and the gaps are either February, or have 30 days.