How to crop to a specific size

I was asked in a recent workshop how to crop an image to a specific size.
If you've used the cropping tool before, you would have seen that there are some handy cropping options including 5x7, 4x5 etc. (photo on right)
In this case I was asked how to crop a photo to exactly 80 x 80 pixels.
This is what needed to be done:

1. Select the cropping tool.
2. From the drop-down menu select "W x H x Resolution"
3.  Enter the width desired in the first box followed by px for pixels or in for inches
4. In the next box do the same for height
5. The last box is for resolution. Because it was for computer display, I entered 72.  If it was for print, I might have entered a much higher resolution of say 300. (I didn't need to add the px or in in this box)

I then resized my crop to select just the part of the photo that I wanted knowing that the final result would be 80 x 80 pixels. When I had my crop in the right spot, I just double clicked to confirm my selection.

The same could have been done using in for inches depending on the planned use of the photo.
Happy cropping!