I have used a classroom money system in my class in the past. It was definetly a learning experience...
Here is a list of what I did...
1. I printed off different coloured and quantity bills.
2. The children sewed their own wallets
3. We learned about money, currency and place value.
4. I explained to the children that if they meet all the expectations for the week they would receive $1, if they didn't they would only receive .50cents.
5. Every Friday I would give out the appropriate amounts to each child and they would either save it for the "store opening" or could put it into a bucket. The buckets was used to collect money the children wanted to donate towards a classroom party or special priveledge.
6. Every month I would open the Classroom Store which had items priced. (My rule of thumb was, if it cost me $2 it would cost them $2). The children would then spend their money or could save it for another month to purchase a more expensive item like a book.
Things that went wrong...
1. Some children were bringing items in from their home and selling for Classroom Bucks to other students
2. Some children were stealing Classroom Bucks from other childrens wallets
3. Some children were not motivated by the system
4. Some children always donated their money to the bucket and therefore didnt have any more left to purchase items from the Classroom Store.
5. Some children never donated their money to the bucket and yet still benefited.
6. It ended up costing me over $300 for the year to run.