Starting to Count with Monetry Denominations

We were at the grocery store, and among all the school supplies, I found flashcards.  I bought the money ones.  They have different coins on the one side, and the total amount on the other side.  MrBaby was a bit disappointed that it wasn't play money, though.  He's been wanting some, but when we got back home, I gave him four one dollar bills.  Then he asked me for a twenty!  Of course I told him no.  I also told him to save his money instead of spending it in the toy machines at the gas station.