http://www.math.umd.edu/~dcarrera/ruby/0.3/chp_02/while.html

The code is as follows:

number = 1
while number < 10_000
  number *= 2
end

number /= 2

puts number.to_s + " is the highest " +\ "power of 2 less than 10,000"

I don't quite understand this, especially since:

a. His program output is clearly not correct. 16 384 is greater than 10
000.

b. His comments don't make sense.

What does this code do exactly?