This is BRILLIANT. Draw a number line with sharpie on a ziploc slider bag and use the slider as the tool to add or subtract two numbers. Awesome!
I LOVE this online lesson planning website. As you create a lesson plan, you note what Common Core Standards apply via a dropdown menu. As a middle school teacher, I create a section for each of my periods and save the documents in the file. So snazzy and FREE! Love it!
Confessions of a Teaching Junkie: The BEST First Day Ever! I may have to use this for the first day/or back to school after winter break
Stomp it - Place value math game (Free idea.)