PBS lesson

It means that if you are in the classroom and you are doing something or doing a project that includes making a mess, you should clean up after yourself when you are done.

During 5th hour chemistry class, Thomas was doing an experiment. He was mixing up fluids and made a huge mess in the science room. The bell rang and instead of just leaving he stayed after class to clean up his mess that he made.

One day Josh decides to bring in a bag of chips and a soda because his teacher said they could bring in food to eat since they were watching a movie. He leaves crumbs all over the floor and in his desk and spilled soda too. He just left the mess.

Example

Carly has finished coloring a picture. She picks up all of her crayons and returns them to her crayon box.

You should clean up after yourself because it is polite, responsible, respectful, and safe. You should never leave a mess in a room, especially soda because someone could slip, fall, and possibly break their neck or any other bones.