Place Value Practice:
http://www.bbc.co.uk/skillswise/numbers/wholenumbers/whatarenumbers/writingbignumbers/game.shtml
http://www.haelmedia.com/html/cw_m54_002.html
http://www.quia.com/mc/279741.html
http://www.berghuis.co.nz/abiator/maths/mc/intmcplvalue1.html
http://www.mrsbogucki.com/aemes/resource/apps/placeval/placeval.htm
http://www.internet4classrooms.com/skills_4th_math.htm
(scroll down to place value links)
http://education.jlab.org/placevalue/
http://www.aaamath.com/B/plc31ex2.htm
http://fen.funbrain.com/cgi-bin/shtml.cgi?A1=../numwords/index.html
http://www.funbrain.com/ofm/index.html
http://www.dositey.com/2008/addsub/Mystery10.htm
http://www.dositey.com/addsub/Mystery10.htm#s