Which account is it on? The Admin account?
You should still be able to see it in your Application folder inside the iWork folder of each account.
If it asks for the admin password when you attempt to open it, just give it the password.
To keep it in view, when it is in the dock, select the icon and right mouse or ctrl click on it and choose "Keep in Dock" from the pop up menu.
If you can not see it at all perhaps somebody has been playing with the parental controls in the System preferences.