Addition and Subtraction

Marshall is a school janitor. Last week, he picked up 844 pieces of trash in the classrooms and 56 piece of trash around the campus. How many pieces of trash did Marshall pick up?

Mr. Bradley donated 31 picture books to the library. Now the library has a total of 455 picture books. How many picture books did the library have before the donation?

After a forest fire, there are 446 old trees, plus 92 baby trees called saplings. How many trees are there in total?

The music school in Washington County held a children's concert and an adult's concert at the same time. A total of 191 students performed at the two concerts. If 69 students performed at the children's concert, how many students performed at the adult's concert?