Posts about combinatorics RSS feed 2019-12-18 12:14Non-Monotonicity in Australian Preference Voting 2019-11-24 16:34Sunday Maths: The Diagonal-Sum Mental Multiplication Method 2019-11-10 01:47Sunday Maths - Quickly Multiplying Teens 2019-11-03 15:49Sunday Maths: Simplifying Squares