iCloud says I have just over 600 photos. On the iPad's storage it says there are just under 300.
However when I go into Apple's Photos.app apparently I have 1800.
I count 900 though. Why are these numbers different and where are the other 900?
Check www.icloud.com and make sure that the 1800 amount is in the Photos section. If so then your iPad may have "optimize storage" turned on.
If the photos arent on there then you need check and see which devices you have and the full amount of photos on them all: Mac, iPhone, iPad & iPod.
Lastly if neither of these situations helped, then contact Apple Support and let them know that there is an inconsistency with whats on your iPad and your Mac vs the iCloud. They may refresh your iCloud account.
On iOS - I like to get my count from Albums - All Photos - check for the total photos count and videos count at the bottom of the thumbnail list.
(I'm at 20,306 Photos and 449 Videos)
On the iPad I have the same except I'm at 20,305 Photos. To get an explanation, go to the Photos view (as opposed to Memories, Shared or Albums) and tap in to a photo.
As you navigate away from the years view in collections, you'll eventually get to a "Moment" and then can scroll to the newest moment and see more details.
On the phone it says "Upload Paused for 1 item" and a blue Resume control if I want to use Cellular Data and finish the upload.
Oddly, the settings app shows 20,318 so I’ve somehow got another dozen “photos”being counted in settings app.