I'd suggest a more hands-on solution.
Children learn about how things work by observing what happens in the PHYSICAL world. They’re learning through their senses. They’re forming mental models of the world. They don’t think about abstract things. Money is mainly abstract.
Get them to make four different clear piggy banks. They’ll be able to see, hear, feel, smell (and hopefully not taste) the ideas behind them. That means this approach involves four senses. It’ll make learning about money easier. And what they learn should stay with them through their whole life.
Collect four clear plastic jars. They can decorate them any way that won’t hide the view of the money inside. Next, label them with these names:
• SAVE
• LITTLE THINGS
• BIG THINGS
• SHARE
They can see the money they’re putting away and watch it build up. They’ll be able to hear, feel, and smell the four separate ideas behind them (SAVE, LITTLE THINGS, BIG THINGS, SHARE).
With money in the LITTLE THINGS jar, they can buy things as soon as they want.
The money in the BIG THINGS jar is for buying more expensive items later.
The SHARE piggy bank sets money aside for them to share with anyone they feel needs it, especially charities.
The SAVE piggy bank is more abstract. The money in it will let them buy assets. These are things that earn them more money without them having to work for it. They can think of it as free money. (Interest via a bank account will do for now. You can look for assets that generate higher returns in the future.)
Ideally, they would be doing chores to earn their pocket money. This would incentivise them to think more about how they use their money. Chores also build up their self-esteem when they see that they're helping their family. For this to happen, you need to show them what they've done right and explain how they've helped. And show genuine appreciation. Building this foundation shapes them into adults that others will value.
Learning how to use money to their advantage is important for children. They need to excel at if they’re going to live a rewarding life. At this age, they can learn basic concepts that they can build on as they grow up.