This activity gets students to think in groups about how many of a certain item there is.
1. Get six bags/containers and fill them with different items. Make sure to count how many of each there are (this is quite time-consuming, but it's worth it to get the real number). I used Post-it Notes, binder clips, stickers, rubber bands, paperclips, and slips of paper.
2. Have the students clear their desks and make lunch groups. Supply each group with an item, a station number card, and one of the attached sheets of paper. Each group nominates one person to write down how many of each object they think there are in the container.
3. Use a timer and decide how much time you want to give them at each station. 45 seconds worked fine for me. Once the timer goes off, students at Station 1 move to Station 2, students at Station 2 move to Station 3, etc. Repeat until each group has a chance at every station and then have them return to their seats.
4. Collect the papers they took notes on and the objects. Write the students' guesses on the board for the first object (in my case, Post-it Notes). Then hold up the container and have them ask you, "How many (Post-it Notes) do you have?" Reply with, "I have (237) (Post-it Notes)." Give a point to the group that had the closest guess. Repeat for the rest of the objects.
*Note+ Students will try and open the containers and count how many there are. Tape the containers closed and remind the students not to open them.