Dementia and counting. How can I divert Dad's attention?

Hopefully, he's in a place that deals with dementia patients and they understand his behavior and know how to redirect him and not let it cause any problem. If the person he is accusing also has dementia, he may not understand what your dad is saying. If he does understand, the facility may need to ensure they don't sit near each other in the dining room or room together if they sense a problem.

When my cousin made comments that I knew were not true, I would assure her that it had been resolved. That made her feel better in the moment. Of course, she would forget and I would have to repeat it the next time, but it worked for the present. I would say, that I had made a call and everything had been fixed. Problem solved. She could never recall what was said the day before. She would give stuff away and then forget that she did it. So, that's why things were missing. Now, she has no idea if anything is missing.

You medicate him. See the Head Nurse ASAP or else Dad will get kicked out for misbehavior.

There's not much you can do, Tinyblu. Even if you convince him for a few minutes that they are all there, he'll go back to thinking some are missing. All you can do is what you are doing. Assure him that they are all there each time he says someone is stealing them. I go through this with obsessions my mother has. My brothers or I may convince her that things are okay, but when the brothers are gone, she falls back to the way she was thinking. Injured brains seem to get stuck in a loop that you can't get them out of.

This situation sounds very frustrating for everyone.

Pulling out the pants and reassuring your dad that they're all there is the logical thing to do. But your dad isn't capable of logic (which you've discovered). You're trying to solve the problem rationally with someone who isn't rational.

You mentioned diversion in your post. Diverting your dad's attention away from the pants situation isn't helpful? When he brings up the pants have you tried to suggest that the two of you go get a cup of coffee and then look for the pants? Just something that will pull his attention away from the pants. Maybe it's a treat you've brought him (that you hang onto until the inevitable pants discussion comes up) or a newspaper that you can read to him in another part of the facility than his room.

When he brings up the pants divert him and lead him away from his room for an activity or treat. A snack might help or a cup of coffee or tea. Whatever your dad enjoys.

Something else that may work is if you bought a couple of the same kind of pants and stashed them in his dresser drawers so when he's looking for them either you or he can "accidently" come across them and be able to say, "Oh, I've found them! They were in here!"

We can't expect our loved ones with dementia to live in our world anymore. We have to go into their world and be with them there. And in your dad's world someone is stealing his trousers. In our world we just count how many pairs of pants we have to make sure they're all there. In your dad's world that's not the solution.

Whatever you end up doing that helps come back and write about it. So many adult children have this problem with their elderly parent.

Well you could try telling him the (imaginary) others are in the laundry or you have taken them home to fix the hem or some such but I have a feeling that wouldn't satisfy him for long either. Perhaps a simple "I'm looking after it" and a change of subject as Sunny suggests is the best option.