ETA: The current Parents Magazine has some articles on teaching kids about money:
http://www.parents.com/kids/responsibility/money-manageme...
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Okay I have 2 kid who are now 6 and 10.
They, since when they were younger than your child, have a "jar" piggy bank. To put coins/bills in.
And they also have a wallet to put things in.
And they have a bank account. Which we need to help them with.
Since my youngest was even younger than 6 years old, we taught my kids about money/saving etc. And there are kiddie books on money, from the kiddie section in bookstores. We have those too.
My kids can put their own money in their own jar piggy banks just fine. Its just a screw top lid.
And they know, what's in it, the amount.
And they also put some money in their wallets. That is to spend. It can be coins or bills that they have gotten as gifts or from us.
And they put some aside to save.
We help them decide how much in each, but we mostly we let them... decide. So they get adept at making decisions.
Even when my daughter (she is the eldest and my kids are 4 years apart) and when her brother was 2 years old, it was no problem.
They knew they each had their own place to put their money. And with a Sharpie pen, we wrote their names on their piggy bank.
So there is no fighting and they do not take each other's money.
Just use some mason jars. Label it with a Sharpie. And that's it.
You don't have to buy expensive things. Just make your own.
My kids, we even let them sell some of their things. And then, THEY got the money from it, we split it up evenly, and they got to save some of it and then spend some of it.