Some of the "better at planning" poor people have built up crude math to make it all makes sense, but seems overly complicated for someone like me. The one I noticed: "oh, I got $85 for selling that pot I made, I'll use that for the fridge repair." - Which is totally different to "oh I got $85, I'll just put it in the pool of my bank balance because I already budgeted for that fridge repair which costs $60". I tried asking this person, but you also needed an extra $10 for that McDonald's lunch you wanted to buy but they insisted "nope, that's my fridge-repair money, can't spend that"
Not sure I'm explaining that properly, but it was the sort of math I encountered dealing with such individuals.
One I've encountered is putting any surplus money into tattoos because they can't be stolen, repossessed or otherwise lost, thus making them a savvy place to put money.
They were completely earnest. The joke followed that they can't take money with them when they die, but they can take tattoos. Pharaohs still have their tattoos, they point out.
There is also a general pattern of spending "extra" money on things like parties, experiences, consumables, etc. Better to spend the money on a pizza party and gocart trip for their kids than to stash it away in a savings account. Better to spend the money on beer for a party than even to hide it under their mattress.
Not sure I'm explaining that properly, but it was the sort of math I encountered dealing with such individuals.