Reference Topics 5-1

This site (courtesy of Rita B. Sowell) provides practice with the basic properties. It is a bit elementary, but if you have having trouble remembering which property is which, this site might help.
http://www.math.com/school/subject2/lessons/S2U2L1GL.html

Vanishing Leprechaun Puzzle
https://services.math.duke.edu/~blake/leprechauns/vanishing_leprechaun2.htm

Vanishing Leprechaun (along with a solution).
http://britton.disted.camosun.bc.ca/jblep1.htm