In their cultural notes in
Sing Chinese, Cindy Mao and Ma Baolin explain that most Chinese children's songs are both entertaining and educational. They tell of some common knowledge in everyday life. This song not only tells little kids that they have two hands and ten fingers, but that they need to be independent by doing there own things.
And all that in an eight-bar ditty, dear surfer! This song is also an ideal medium for learning music as it gently ascends and descends the scale of D between D and B.