What is the central unit of the computer that contains the logic circuitry and carries out the instructions of the computer's programs called?

Create a word problem that involves calculating the volume and surface area of a three-dimensional object. cube: surface area 6 s2 , volume s3

Im doing this last minute and literally none of my neighbors or people that my dad works with use excel so if anyone could me make up an example

The first screen you see when you open word2016 what is called?