Why are numbers from -32768 to 32767 stored in two bytes?

Question

C++ / C#

I study programming. There is a data type with inta size of two bytes. The numbers will be -32768up to 32767.
How do I calculate that two bytes is that number and for the other 4 bytes, etc.

Answer 1

2 bytes = 16 bits. 2^16 = 65536 or -32768 to 32767. Continue by analogy)