Teachers are spending their own money to make sure their students have what they need.
A report from My E-learning World says that they average teacher spends $820 out-of-pocket on their classrooms every year.
The majority of that money goes toward supplies like books and software.
Teachers also spend their own money on classroom décor, pencils, paper, food and snacks, prizes, and cleaning supplies.
The report says that across the US, teachers will spend $3.2 billion on their classrooms.