Integers: unsigned binary
How many possible values are there for 32-bit unsigned binary representation?
There are 232 different representations, so there are about 4 billion possible values
Why 4 billion?
Why do we say possible values?
Minimum value: 0
Maximum value: 232 - 1 (approximately 4 billion)
In general, for N bits, the max value is 2N - 1
Why -1, since there are 2N representations?
Think of array of size 2N.  What is the largest index?