( ( Calculate ( ( the ( percentage composition ) ) ( of ( a compound ) ) ) ) . )
(ROOT (S (VP (VB Calculate) (NP (NP (DT the) (NN percentage) (NN composition)) (PP (IN of) (NP (DT a) (NN compound))))) (. .)))
Calculate the percentage composition of a compound.
(ROOT (S (NP (DT The) (NN term) (NN percent) (NN composition)) (VP (VBZ means) (NP (DT the) (NN percentage)) (PP (IN by) (NP (NP (NN mass)) (PP (IN of) (NP (NP (DT each) (NN element)) (PP (IN in) (NP (DT a) (NN compound)))))))) (. .)))