In order to get to the secret room (the blueprint is in Nate's locker), you have to go through the filing cabinet in the Detention Room.
Once you have concocted a stink bomb (in the Science Lab), chew your gum in the school and you will be taken to Detention. Set off the stink bomb and the teacher departs, leaving you free to access the filing cabinet and secret room (the missing bell clapper is there!).
(see related question)
On Big Nate's island
big nate island has lots of gum included!
You eat it.
all you have to do to get a pack of gum is: on Big Nate Island you have to collect all of the big nate comic book pieces.
On Big Nate island, you have to go into the Komix Shop, and talk to the guy, then find all of the Big Nate comic pieces, assemble them, and give them to him. Then he'll give you gum. *Various kinds of "effects" using gum are also available in the Store, but do not have anything to do with Big Nate Island.
chew it in school and go to detention
get some gum in a mini-game from nate and go to the school.then go to detention and chew the gum
Chew the bubble gum
To get the gum in Big Nate Island, you must complete the comic sheet and give it to the man in a tan shirt. You can find him in the "Klassic Komix" store. When you start the island you must go to him first so he can give you a piece of the comic. After you've completed the comic, give it to him and he'll give you gum.
All around big nate island. You have to find it.
You just chew bubble gum then the teacher yells at you.
you get the comic pisis then put it together and give it to the man in the big nate bilding and get the gum.