A friend of mine sent me the photo below of a Sears Craftsman reciprocating saw.
What do you suppose the yellow switch does? Since the positions are labeled ‘0’ and ‘1’, my first thought was that they were off and on respectively. But no!
The yellow switch controls blade operation: normal versus orbital. But which label corresponds to which operation? You can’t tell before you turn on the saw, and even while it’s running it’s not obvious. But you can tell if you watch the blade closely as it slows down after you turn the saw off.
The printed instructions that came with the saw say:
The first position is for normal blade operation, and the second position is for orbital blade operation.
But which is “first”, the position labeled ‘0’ or ‘1’? A normal human being might think that 1 and 1st go together. Being a programmer, I assumed—correctly—that 0 is the 1st position.