How do I crop by values?

[rich2005]

(Yesterday, 11:32 AM)Steve_k2400 Wrote: Hi!
I would like to crop an image by entering the values in the crop dialog box.
The values I'm looking for is Position X/Position Y and Size X and Size Y.
These values describing the cropping area and should be enough but:

- when I try to enter values in the corresponding fields, my image is zooming. Regardless if I use the NumPad or the normal numbers. I'm not able to input the numbers.
  What is the way to enter the value fields and be able to put numbers in it? 

- when I was able to somehow enter those numbers I can't see a way to execute the crop. When I click in the image, it will reset these values.
  How do I actually initiate the crop after I entered the values?

All the tutorials in the net show the interactive way to crop but I could not find any that shows how to do it just by numbers.

Thanks for any suggestion.

quote- when I was able to somehow enter those numbers I can't see a way to execute the crop. When I click in the image, it will reset these values.
How do I actually initiate the crop after I entered the values?
I think that is your problem, you have not actually initiated a crop. You can set a fixed size in the dialogue, and you get that when you click in the canvas, but you still have to set the origin, thus.....

I can only describe how I procede.
Using the crop tool, draw the crop area (any old area) in the canvas.

Now using the dialogue, 
Set Delete cropped pixels
Next to position set px (pixels) This could be your problem if set to say percentage
Enter the position, which is the top left corner and the size. 
Enter the size, again make sure px is set  against size and enter the size for each side. Hit enter to fix.

Then to apply the crop, click on the canvas inside the crop area.

This a 50 second example: https://i.imgur.com/vOKjTT1.mp4 Hope it helps.