I am curious to see how parents who are on benefits teach the children about money
I think that whatever your income, and wherever it is from, the same principles apply. Or at least possibly until you get into the realms of wealth where there is no budget.
If you are talking about financial education from young, that is where pocket money comes in, even if it is £1 a week. Working with children to understand the "when it's gone, it's gone" idea, and the concept of saving up for something, etc. Also that rather than buying a 'new' book at the school book fair, you could take the same £10 and buy 10 books at the charity shop, or put the note in your pocket and get them free from the library. All things you model for them, explain to them, and let them experience.
I realise this gets more difficult as cash gets used in fewer places. When my dc were at (secondary) school, they had their dinner money for the week, and had to manage it. If they bought fizzy drinks or extra cookies at break, they would not be able to afford a proper dinner towards the end of the week. If they took cereal bars or fruit from home, they saved more. If they chose a jacket potato and beans over the roast one day, they saved. By the time my youngest went to 6th form, it was cashless, and they didn't have that concept of 'cash in the pocket'. Lots of things can be taught 'in theory', but actually experiencing things sticks a lot better for most people.
Same with encouraging them to get part time jobs. It isn't just that they are earning money in their teens (which is good) it is that they "feel" how many hours of flipping burgers you need to do to buy that particular brand of trainers, or that concert ticket, or whatever expensive thing they are in to. Then understanding that the more 'attractive' job on paper, that involves you having to get the train to the City Centre, actually means you have less time and less money in your pocket than the less appealing job on your doorstep.