GDP is a measure of a country's **production**.

$$GDP = C + I + G + X\_n$$

$C$ = Consumer Consumption  

$I$ = Gross Investment  

$G$ = Government Expenditures  

$X\_n$ = Exports - Imports

Exports are what we produce and make a profit from by selling to buyers outside our country. Imports are not produced by our country, so it shouldn't be included in the GDP, so it makes sense to **exclude** it from the calculation; ie. there should be no "- imports" in the calculation.

However, the calculation **subtracts** imports from the GDP. Imports somehow take away from what we produced? That seems to say, calculate how much I have produced, X, and then don't count some of it because I imported Y. Which doesn't make sense given that importing doesn't remove goods and services that have already been produced!

For example, let's say I can take apples and make pies... I produced value in the form of the "pie" quality. Importing the "pie" quality and tacking it on an apple creates an apple pie. However, I didn't make that "pie" so I can understand how it doesn't get included in the GDP: the value of the "pie" quality was not produced in this country, so it isn't included in the GDP. 

Let's also say my GDP = "made a cat meow" + "turned a tree into a fountain". Somehow, by importing the "pie" quality, I am to ignore some of the value of making a cat meow?