Same as `hih`, except you release your thumb and pull in your index finger. It is just like going from ``one`` to ``two``, except in this case, it is all with your little finger pulled in - so you have `gee` (or sixteen) plus one and two respectively, which gives us hih and jih (or seventeen and eighteen, respectively).
Thumb and index finger down, all other digits up.
|||| |||| |||| |||| ||
Thumb: |||| |||| |||| |||| - worth "g" - or sixteen
Index finger: || - worth 2