This is a great book that presents Chinese radicals in an easy and rhythmic way.Altogether it introduces 172 radicals. The  first part uses free radicals to make up 56 verses, which are choosen from the most frequently-used radicals that are characters by themselves. The second part uses bound radicals to make up 20  verses, which mainly deal with those radicals that are not characters by themselves, but the variations of the characters through derivation or simplification.