Nothing but a no-good basehead

True story from today. A coworker, in all seriousness, believed the following method was how you converted from base-10 notation to base-2 notation:

• Take any number, e.g. 131.
• Perform an explicit expansion, e.g. (1 x 10^2) + (3 x 10^1) + (1 x 10^0)
• Replace every instance of 10 with 2, e.g. (1 x 2^2) + (3 x 2^1) + (1 x 2^0)
• Re-evaluate the expression, e.g. 4 + 6 + 1 = 11
• Thus, 131 is represented in base 2 as 11.

The punchline to this story is that this coworker has an engineering PhD.