THe margin of victory

So many of the kids were excited about the election.
They all knew Obama won.
So I presented the numbers for the popular vote on the board
55542743
62680702

First I asked them to read the numbers.... no problem although two students said "You forgot to put the commas in."
OkThen we talked about the margin of victory and one student then figured that was the difference.
OKThen I asked them to estimate the margin of victory.
And they froze!
What number do we round to? Some thought hundred place...some decided hundred thousand. No one picked million or lead digit. When I asked why they had made the choice they did, they did not have a clear answer.
One said he rounded to the first big number.... hundred place.

One said hundred thousand place because that is what most of our problems had looked like.

To think about.... how to tell what is the best place to round to? How is estimation used in the real world?