Mental math pseudo-random number generators

For some reason, thinking about doing algorithms mentally really confused me for a second and I started wondering about whether updating the state variable would cause flash memory wear in my head. Hopefully that's not a thing! Or is it?

I wonder if there's a multiplication-free version that doesn't require going back and learning the 6 column of the times table, and takes advantage of the free "salts" we already track as the date of the month, our age, etc.

Especially if it could be done without double digit math.

Maybe add 7 to X mod 10, and 3 to Y mod 10, then add both together?

56, 29, 92, 65,38

11, 11, 11, 11, 11

Hey wait a minute! RNGs are hard!!! What is this sequence?