12 is the median age of the kids at my camp. There are 10 kids who are older than 12 and 10 kids who are younger than 12.

Step-by-step explanation:

Remember that the median represents the value at the middle, literally.

So, if 12 is the median, it means is the value at the center of the data set.

Now, according to the problem, there are 10 kids older than 12 and 10 kids younger than 12. That means there are 24 kids who doesn't have 12 years old.

Therefore, there are 25 kids in total.