Teaching numbers can be hard for the younger set. Once they master up to twenty it gets easier. I recently used Un Alce, Veinte Ratones to review numbers 1-20 with one of my young Spanish students. It worked out better than I had hoped! Here's what I did:
First I read the story to her. She was already familiar with the numbers and could count easily from one to twenty, but she is still working on identifying numbers that are out of order and just recognizing which numbers are what. It's one thing to be able to count out loud. It is another thing to be able to see a number and recognize what it is. So after reading the story to her I pulled out some number cards, put them in order and had her count 1 through 20 with the cards.
I then randomly picked a page and had her count the animals on that page. She then had to look at the number on the page and find that same number on one of the number cards and hand it to me.
We did every page randomly until I had collected all the number cards from her. I was amazed that she didn't get bored yet in the process she was counting over and over again and also working on recognizing the way numbers are written.