'IDE' is short for 'Integrated Development Environment'. It's where we'll code.
Instructions:
The numeric operators are two place functions that take two numbers and return a third. They are placed between their arguments, i.e. they are infix.
We can give names to values. This allows us to store those values away and use them later.
A function takes a value or values, performs a computation and then returns a value. Consider the square root function.