The problem:
Which of these numbers is the odd one out? Why?
These children chose 8. Seth said, "It is the only one with 1 number."
This group thought that 66 was the odd number. Jenson explained that it is the only number with 2 digits the same.
These children thought that 25 was the odd one out. Carla and Zane both explained that 25 was the only number that can't be divided by 2.
The final group thought that 120 was the odd one out. Leah explained that it was the only 3 digit number.