Question

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?

Answer 1

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".