I don't get it

Donald Rumsfeld is giving President Bush his daily briefing. He concludes by saying: "Yesterday, 3 Brazilian soldiers were killed."
"Oh no!" the President exclaims. "That's just terrible!"
His staff sits stunned at this uncharacteristic display of emotion, nervously watching as the President sits, head in hands. Finally, the President looks up and asks, "How many is a brazillion?"