Someone wrote, the kids know that if they do mitzvos ….
I feel that they should be taught more than just reward and punishment. Some kids don’t care about it. They should Also be taught that just like Hashem gives us food for our body, He also gave us mitzvos for our soul to help us connect to Him.
If they are not interested for themselves, then we can also mention that our mitzvos help the world by bringing blessings to the world.