This is the best color by number book for kids by far! My 4 year old grandson absolutely loved it. I bought it for him for Christmas and he finished it in June. There are 50 one-sided pictures to color, suitable for crayons. The coloring area are smaller, but great for 4-5 year olds. There are no large boring areas of one color to do. It uses a variety of colors, but a 24 pack of crayons will cover it. My only quibble, and it is a small one, is that the pictures are all underwater scenes so that you will use a lot of blue. No other coloring book comes close!