Posted: January 23, 2014
http://resources.oswego.org/games/Estimate/estimate.html
http://www.mathopolis.com/games/estimate-add10s.php
http://www.theproblemsite.com/junior/estimation.asp
http://www.ictgames.com/helipad%20hops7.html
http://www.mangahigh.com/en-us/games/iceicemaybe
http://www.mathsisfun.com/numbers/estimation-game.php Use Count 20-99