This card game is a great tool to use in math workshop. All you need is a deck of playing cards. You need to make a trip to the dollar store for that! But I especially love using it at the beginning of the school year to teach collaboration and cooperation. This video gives instructions for playing it. You can't lose here. It hones mental math skills and gives you an opportunity to observe your kids in action, together. It's perfect for math centers, too.
YOU can download this video as a supporting document, in order to upload it to a Google site for student use.