Math Game - Number Guess

So I mentioned yesterday about the math activity I was going to do today.  I purchased Avery Cord Style Name Badges, downloaded template #74465, and then typed one- to three-digit numbers - one number per card.  I just printed these on normal paper and paper cut them to 4" X 3" rather than wasting the nice perforated ones enclosed.  Then I slid one number in each plastic pouch.  During math class, I put one of these cord badges around the students' necks with the card on their back so they couldn't see their own numbers.

Now the children walked around with a post-it note to take notes (if they wanted) and they could ask yes/no questions - but only one for each student until they figured out their number.  Once everyone was successful, we discussed what kind of questions were very helpful.  For example, some children asked: "Is it 38?"  "Is it 217?"  Not very useful questions.  Some asked:  "Is it odd?"  "Is it 3 digit?" "Is it higher than 500?"  This provided them with more useful information.  It was an interesting and fun activity for everyone!  (I did, of course, rig the numbers - easier ones for those who needed it.)  Enjoy!