"They must have a lot of extra fingers and toes to count that high...."
And all the toes and fingers had to be counted multiple times, in order to reach that grand total, (sort of like votes in California's peculiar "vote harvesting" election system).
Compounding the issue, some hands and feet in the world have a non-standard number of fingers or toes, so that tended to throw off these scientists, and skew the subtotals.
(Keeping all the people in the world lined up and barefoot for that counting process also was quite a challenge for these moonbeamer scientists.)