Station  11C

Addition 

To add three numbers, say, $106$, $51$, and $42$, represent each number on its own row of the board using counters as dots in a $1 \leftarrow 2$ machine. (Of course, Napier did not use our language of Exploding Dots and their machines, but it is clear how our language translates to actions to do with physical counters on the board.)

Then slide all the dots down to the bottom row and perform the usual $1 \leftarrow 2$ explosion rule to read off the final answer.