The author describes thinking of 9 as floating around looking for a 1 to chomp off another number. This is very clearly designed to support good intuitions about adding in base 10, but it produces bad intuitions about binary numbers, multiplication, polynomials, etc. If faced with myriad other problems that involve 9, like, say: "which is bigger: 2^9 or 9^2?" or "how should we store words from an alphabet with 9 characters in memory?" or "how can we distribute 9 things equally?" or "for which n is 9^n + 2 prime?" or "how should we expect an atom to act if it has 9 electrons?", a completely different way of looking at the number 9 is warranted. In that last case, the exact opposite is true: 9 is desperately trying to rid itself of a 1, not find another 1 to grab.