Explain how to estimate 586 - 321 two different ways

My guess this is answer I hope it is right

One way is to round to the nearest ten first then subtract. 1
Another way is to round to the nearest hundred then subtract. 2
And one more way is to subtract then round to the nearest ten. 3
The last way is to subtract then round to the nearest hundred. 4

Example of #1 - 590-320 = 270
Example of #2 - 600-300 = 300
Example of #3 - 586-321 = 265 = 270
Example of #4 - 586-321 = 265 = 300

All of these should work it just depends on what your teacher wants. Choose any of the examples.

HOPE THIS HELPED :)