If you want to play several games at once against your students, or maybe you just want to challenge yourself with multiple games at once, if you are a premium member, you can do this at Chess.com! Here is Danny Rensch explaining how:

To play multiple games at once, you must be in live chess: https://www.chess.com/live

Click on the options gear icon at the top right of the chess board:

In the next menu, click on the 'play' tab, and then toggle the switch for multiple games:

When you turn on the Multiple Games switch, another option will appear to auto switch games. When this option is on, after each move you will automatically be taken to the next game where it is your turn with the least time remaining. This option will not prevent you from manually switching between games as well.

Once these options are both turned on, you will be able to accept multiple challenges from all your students or friends!