I have heard a couple of different versions of this joke. This version comes from Feld Thoughts.
Donald Rumsfeld is giving the President his daily briefing on Iraq.
He concludes by saying: “Yesterday, 3 Brazilian soldiers were killed.”
“OH NO!” the President exclaims. “That’s terrible!”
His staff sits stunned at this display of emotion, nervously watching as the President sits, head in hands.
Finally, President looks up and asks, “How many is a brazillion?”