I wonder if it would be clearer to define the byte as having 8 bits? In the text it says
byte b = B10010; // "B" is the binary formatter (B10010 = 18 decimal)
I'd have thought we should see
byte b = B00010010; // "B" is the binary formatter (B00010010 = 18 decimal)
Otherwise there is a possibility that people might forget about the leading zeros.