Group 1:
http://www.thatquiz.org/tq-0/
http://www.math6.nelson.com/quizzes/math6quizzes/gr6_ch1_les4.htm
Group 2:
http://henryanker.com/Math/Computation/Order_of_Operations/Order_of_Operations_Set_3.swf
http://mdk12.org/scripts/hsa_practice_taking.plx?year=2007&dir=/assessments/high_school/look_like/2007/algebra/minitest1/&subj=alg
Group 3
http://perspective.pearsonaccess.com/content/resources/learningresources/ma/viewresource2.html?html=5428/index.htm