Definition: The associative property states that you can add or multiply regardless of how the numbers are grouped. By 'grouped' we mean 'how you use parenthesis'. In other words, if you are adding or multiplying it does not matter where you put the parenthesis.
Full Definition of ROSIN. : a translucent amber-colored to almost black brittle friable resin that is obtained from the oleoresin or deadwood of pine trees or from tall oil and used especially in making varnish.
Rosin paper is also commonly used as general purpose protective sheathing. If you are performing home renovations, for instance, you can lay rosin paper over furniture and other surfaces to protect them from becoming inundated with dust.