1) This website provides you with 20 free math problems per day. It is easy to navigate and provides a lot of extra practice.
2) Pouring and Filling
http://media.pearsoncmg.com/curriculum/math/cmp3/activities/A82404/
3) Quadrilateral Exploration
http://www.mathsisfun.com/quadrilaterals.html
4) Quadrilateral Game
http://www.sheppardsoftware.com/mathgames/geometry/shapeshoot/QuadShapesShoot.htm
5) CPM Key-In-The-Lock Puzzle
http://technology.cpm.org/general/keylock/
6) CPM Parent Guide
https://pdfs.cpm.org/CoreConnections/ParentGuide/cc3/CC3_PG.pdf