My boy loves dog and cat when he started to learn animals' sounds. This book is entitled with I Count to 100 and colourfully completed with cats and dogs in various sizes. Basically, i realized that the publisher (and the author) designed this book for 5+ years old children as the curriculum where the publisher is located (let's say UK) set up the counting 10s to 100 is made for 5+ years old students. But, when my son first time saw this book, he was so happy--not because he started to learn the counting, but the way the author and the illustrator grouping the things (dog, cat, dino, cake, car) in 10s in one colour. This made my son easy to imagine the 'basic concept' in math: categorizing & grouping. I recommend this book for 2+ y.o not for learning how to count, but how to understand deeper: categorizing & grouping.