Here are the PDF files that I used at the MEI conference.Circle cards - The group work activity. All 4 sets of cards.
Straight line eureka - the instructions for using Geogebra and the activity sheet
Straight line eureka worksheet - the student sheet for the above activity
Fine tuning straight lines - the activity sheet
Fine tuning straight lines worksheet - the student sheet for the above activity
Quadratic curves - the instructions for the deep thought activity using Geogebra