The list is so long! For me making sure students have to think and make connections. Showing the beauty of the subject and the practical uses. Highlighting hidden maths. Puzzles, problems, challenges, and games, but using these kinds of activities with a reason – finding the maths underneath them.
Often challenging pupils beliefs… for example many say that there are 180 degrees inside a triangle… but what if you stood at the north pole and walked to the equator, walked around a quarter of the equator and then back to the north pole…. what is each angle in the traced triangle.