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.
A lighter, powdered cake of rosin is used for violins. Applying rosin to the bow of the violin is a crucial step in achieving the correct sound and prolongs the lifespan of the instrument. Invest in high-quality rosin, and apply it every time you play the violin.