# Difference Of Squares Find the difference between the square of the sum and the sum of the squares of the first N natural numbers. The square of the sum of the first ten natural numbers is (1 + 2 + ... + 10)² = 55² = 3025. The sum of the squares of the first ten natural numbers is 1² + 2² + ... + 10² = 385. Hence the difference between the square of the sum of the first ten natural numbers and the sum of the squares of the first ten natural numbers is 3025 - 385 = 2640. ## Setup There are two different methods of getting set up to run the tests with Objective-C: - Create an Xcode project with a test target which will run the tests. - Use the ruby gem `objc` as a test runner utility. Both are described in more detail here: http://exercism.io/languages/objective-c ### Submitting Exercises When submitting an exercise, make sure your solution file is in the same directory as the test code. For example, if you're submitting `Bob.m` for the Bob exercise, the submit command would be something like `exercism submit /objective-c/bob/Bob.m`. ## Source Problem 6 at Project Euler [http://projecteuler.net/problem=6](http://projecteuler.net/problem=6) ## Submitting Incomplete Solutions It's possible to submit an incomplete solution so you can see how others have completed the exercise.