Numbers Hide and Seek by TouchyBooks is a great number recognition book perfect for ages 2-4. I had originally thought that this book would be a type of I Spy book; however, the numbers were mostly 'hidding' in plain sight. This was a good thing for my three year old LaLa who was so excited that she could find them "by my ownself!"
I liked that each number (1-10) had an introduction page that gave a rhyme which would hint to its location on the page. The kids liked that number 4 won the boat race every time (yes, every time! do we really have to try it more than 20 times?!). They also found it hysterical that number 5 with a "big fat belly" would burp when they touched him. LaLa just loved the number 10 page where the number one married the number 0 to create Mr. and Mrs. 10.
Numbers Hide and Seek is great if you have a young child who is just learning his/her numbers, or needs a review of the visual representation of numbers 1-10.