Desmos

Being a Math teacher turned instructional technology teacher I could not have been happier to see such a wonderful web tool as Desmos, an online graphing calculator.  It will do almost everything a $100 plus graphing calculator will do and sometime more.  It is based on html 5 code so it works on all mobile devices and does not use a lot of broad band.  On YouTube, Desmos has their own channel where you can learn more about the graphing calculator and all that can be accomplished using this wonderful tool.  They even have google account tie in so if your school has Google Apps for education, you can have your students use their district provide accounts to save graphs as part of their assignment without having to create an account on their own potentially.

Then one of my favorite bloggers tweeted this on March 5, 2013 about an offshoot using Desmos which led me to Daily Desmos.  This site challenges you to match different graphs using Desmos and then send them your solutions.  This would be a perfect way to challenge your high level students.

Daily Desmos. Another creative single-serving website from the ever-creative math edublogotwitterwhateversphere. bit.ly/10av4Q7
— Dan Meyer (@ddmeyer) March 5, 2013