How would you use a number line to round 16800 to the nearest ten thousand?

Well you'd see if it's closer to 10000 or 20000.

In this case it would round to 20000.

4000

Step-by-step explanation:

Numbers that have the last three digits of 500 or more should be rounded up to the next even thousand. Numbers that are under 500 should be rounded down to the nearest thousand.

Hope this helps!