Superadditivity

Superadditivity is a big word that means when you put two things together, the result is more than just adding up those two things by themselves.

Let's imagine you have two toys, a car and a ball. You like playing with the car and the ball separately, but when you play with them together, it's even better! You can roll the ball towards the car and watch it bump into the car and change direction. This new experience is superadditive because it is better than just playing with the car or the ball alone.

In math, superadditivity works the same way. Imagine you have two bags of candy. One bag has 5 pieces of candy and the other bag has 10 pieces of candy. If you add those two bags together, you would expect to have 15 pieces of candy, right? Well, sometimes superadditivity happens and you end up with more than 15 pieces of candy! Maybe some pieces from one bag fit perfectly in the gaps of the other bag, or maybe some candies stick together to make bigger candy pieces, or maybe one bag has some candies that the other doesn't, making the whole collection more valuable. This is why superadditivity is sometimes called "the whole is greater than the sum of its parts".

So, next time you play with toys or count your candies, remember that sometimes putting two things together can make something even better!