About 200 words
When I went to school, the flag had 48 stars in a neat 6-by-8 pattern (handy for learning multiplication tables) and biology teachers made us learn that the human cell had 48 chromosomes (neatly arranged in two dozen pairs). Somehow, since then, the flag gained two stars and the human cell lost two chromosomes! There are now 50 stars on the flag. The official, certified number of chromosomes in the human cell is no longer 48 but 46.
For many years, scientists were absolutely certain that 48 was the correct number of human chromosomes. This nice, round, factorable, pleasant number was promulgated, promoted, and printed in myriad textbooks. I imagine that, for decades, some medical reasearch students were required to "see" all 48 through their microscope oculars, at peril of flunking their laboratory exercises in karyotyping.
Sometime later, the mistake was caught and corrected, and by now all textbooks and most M.D.s and researchers have since caught up with the new truth. The loss of two chromosomes was offset by the gain of two stars. Balance and order have been restored, and all is right with the world -- at least until a new state is admitted to the Union.