It all started when Dan Meyer tweeted this Which One Doesn’t Belong prompt…

Math & contrasting cases collide in @WODBMath. Here is my contribution! What do you think? Which one doesn’t belong?! pic.twitter.com/jnrp8qVLpQ — Dan Meyer (@ddmeyer) March 23, 2015

The MathTwitterBlogosphere had a ball using logical and comical thinking to conceive of ways to not pick the muppet. I said Daniel Craig didn’t belong because his hands were showing. Then I decided to send a response…

@ddmeyer@cmmteach@TracyZager@WODBMath@JustinAion Hey Dan, I found one where the answer is still snarf! pic.twitter.com/2M6QkBDiYu — Andrew Gael (@bkdidact) March 23, 2015

But all the fun and games got me thinking about my own classes and how I could leverage this fun for my students. Enter Mary Bourassa and her new #MTBoS site Which One Doesn’t Belong? Inspired by the work of Christopher Danielson, Steve Wyborney, and Chris Hunter, Mary has created a wonderful new website meant to spark mathematical conversations and debates among students and teachers. It joins a list of other #MTBoS inspired websites that provide prompts for beginning of class activities. Beginning of class activities are called many different things: do nows, openers, bellwork, warm-ups, but I like to refer to them as daily routines.