Answer:
Ken's misunderstanding is that you have to round starting from the 1st number that is behind what your rounding to. In this case Ken needs to start from 1 and round instead of starting from 3. So you would round the 9,000 by looking at the 1 and seeing if you should round up or down. You want to round down because 1 is less than 5. If Ken rounds from 1 the real answer should be 9,000
Explanation: