I think I am going to distract my classmate by browsing on my computer
Why would you want to distract your classmates?
I'm bored and have nothing better to do.
It's not very polite to attempt to distract classmates who might be really invested in learning. It would be better to respect their education and leave them be, while trying to find something on your own to do.
The class is super boring and I already know everything in this class so I have nothing else to do.
The class is super boring because you are super smart! However, your friends might think it's interesting and want to learn, and they deserve a chance to enjoy the class. While this boring class is going on, why not study for another class that you enjoy, which will keep you busy and allow you to complete your homework ahead of time?