Upper/ lower case letters card game

Lately, M and I have been working on matching lower and upper case letters. To help her practice, I've made a set of cards that have upper case on one side and lower on the other. This is how our little game goes:

I spread four or five lower case letters in front of her.

Me: Can you find the baby (B)?
M: (points)
Me: Let's see if you're right
M: (turns over the card)
Me: Is that a (B)?

If she is right then we leave it upturned. Once all of the baby letters are capitals M gets the fun of smearing them all around while we say, "Yay! You did it!" (seems to work as a motivator :-)