Possible copy error in explain example

I was looking at:
http://candle.pha.pa.us/main/writings/pgsql/sgml/performance-tips.html

And noticed in the first example that it is claimed the cost estimate
is 233 disk block reads. However, "233" doesn't appear in the explain
output shown. I think that "233" is supposed to match the "333" in
the explain output, but I am not 100% sure.