Fix unclear wording in difference of squares

Author: kytrinyx

difference-of-squares.md

@@ -1,10 +1,12 @@
+The square of the sum of the first ten natural numbers is,
+
+    (1 + 2 + ... + 10)**2 = 55**2 = 3025
+
 The sum of the squares of the first ten natural numbers is,
 
     1**2 + 2**2 + ... + 10**2 = 385
 
-The square of the sum of the first ten natural numbers is,
-
-    (1 + 2 + ... + 10)**2 = 55**2 = 3025
+Hence the difference between the square of the sum of the first
+ten natural numbers and the sum of the squares is 2640:
 
-Hence the difference between the sum of the squares of the first ten
-natural numbers and the square of the sum is 3025 - 385 = 2640.
+    3025 - 385 = 2640