Given a math word problem, answer the following question. You might need to apply addition or subtraction mathematical operators on the numbers embedded in the text to answer the question and then only report the final numerical answer.

[Q]: henry had $ 54 . later he sold some of his old toys and got another $ 2 . how much money does he have total ?
[A]: 56

[Q]: professor treehead of the flora university requested his students to participate . he said that they planted 15 species of trees in the natural park 20 species of trees in the neighboring forest and 10 species of trees all around different locations in town . how many species of trees were planted by the students ?
[A]: 45

[Q]: maria was buying dvds of her old favorite tv series . she bought 8 dvds at the store and she bought 2 online . how many dvds did she buy total ?
[A]:
10