How do delete photos from ONE DEVICE only, leave it on iCloud?

Hi,

I have an iPad that I wanna give to my son to use, it is synced to my Apple ID, and iCloud. I wanna DELETE all iCloud synced photos on the device, WITHOUT them being deleted elsewhere. Then, I do NOT WANT any "new" iPhone photos to appear on the iPad.

HOW DO I DO THAT?!

If I unchecked "iCloud - iCloud Photos", and THEN deleted the pics, would it NOT delete off iCloud? I just tested that, and my NEW iPhone photos appeared on the iPad, so at least in that direction it doesn't work.

Any way to fix this?

Thanks