Blaine county, idaho, has a population of more than 20,000 people. what is the order of magnitude for the number of people living in this county?

The order of magnitude is essentially the number of powers of 10, which means that numbers 1-10 have an order of magnitude 1.

Then numbers 11-100 have an order of magnitude 2.
Then numbers 111-1000 have an order of magnitude 3.
Then numbers 1111-10000 have an order of magnitude 4.
Then numbers 11111-100000 have an order of magnitude 5.

And our number is in the last part! so the answer is "5".