This quick activity is a nice early lesson for toddlers on spotting the difference (a.k.a. the odd one out), which is a starting step for later visual perception and attention to detail.
For this super-simple toddler version, I put stickers on index cards, always using several of one kind and one oddball.
I started with a version that focused on color difference, using all star-shaped stickers: 4 of one color and the outlier hidden somewhere among them.
She was quick to tell me the dominant color out loud (i.e. “Green!”), which told me that her eye was quickly spotting the majority. Each time I told her, “Look, the purple is different,” to bring her focus in that direction.
Then we moved on to a version with vehicle stickers. Here, I had three of a kind and one oddball. Again, her eye always went to what was dominant, naming it for me. “I see a car!”
Sometimes I almost felt like she couldn’t see the oddball at all, even after I named it!
It became clear that the game was a little advanced for her, too, because inevitably she wanted to hold a sticker, and this was a bigger draw than my insistence on, “Look, the bus is different. There’s only one bus.”
Note: You can also draw the images, if you don’t have stickers on hand. Try smiley faces with one sad face, for example, or circles followed by one triangle. If you want your cards to be more permanent, cover them with contact paper.
One way or another, this is a fun intro to the concept.