All Math Concepts:
Livebinder full of math resources http://livebinders.com/play/play_or_edit/17303
Math tutorials for all units http://www.learnalberta.ca/content/me5l/html/math5.html
Math Concepts http://www.harcourtschool.com/thinkmath/grade_3.html
Measurement:
Measure it http://www.funbrain.com/measure/index.html
Measurement Practice http://www.apples4theteacher.com/measure.html
Several Measurement Games http://jmathpage.com/JIMSMeasurementpage.html
Animal Weigh in http://www.bbc.co.uk/education/mathsfile/shockwave/games/animal.html
Soda Fountain http://www.mrnussbaum.com/soda.htm
Centimeter Measurement http://www.funbrain.com/cgi-bin/meas.cgi?A1=s&A2=1&A3=0&COBR=2
Customary Measurement Match up http://www.hbschool.com/activity/con_math/g04c24.html
Postal Measurement http://www.bbc.co.uk/schools/ks2bitesize/maths/shape_space/measures/play.shtml
Measurement Rap by a teacher http://www.teachertube.com/viewVideo.php?video_id=155&title=Mrs__Burk_s_Measurement_Rap