To answer this question, please refer to the picture mentioned in the main question. The number of children who did not go to the park, their names, and where they went would be found there.
Example Answer (if the picture showed 2 children, named Harry and Isla, who went to the cinema):
There were 2 children who didn't go to the park: Harry and Isla. They went to the cinema.
Note: Please provide the picture for a definitive answer.