  The Chow ring of the moduli space of marked rational curves is generated by
Keel's divisor classes. The top graded part of this Chow ring is isomorphic to
the integers, generated by the class of a single point. In this paper, we give
an algorithm for computing the intersection degree of tuples of Keel's divisor
classes. This computation is a concrete but complicated algorithmic question in
the field. Also, we give a simple complexity argument for the algorithm.
Additionally, we introduce three identities on multinomial coefficients, as
well as proofs for them.
