Tree Diagrams - Pom Poms Help!

We learned about determining probability in multistage experiments. She had us use tree diagrams to help.  The most helpful thing though was she gave us pom poms to use so we could actually do the experiment instead of just dealing with numbers on a paper.

The question was:

"A box contains three white balls and two colored balls.  A ball is drawn at random from the box and not replaced.  Then a second ball is drawn from the box.  Find the probability that the two balls are different colors."

The diagram was so much easier to draw and understand when we could actually do what the question was asking.

Here is a page on Math Is Fun that explains tree diagrams and probability:

Math Is Fun - Probability Tree Diagram

One of the things that I really like about my teacher is that she is not only teaching us the math, but is giving us hands-on activities and advice that we will be able to use with our own students.  She explained that pom poms are great - they are cheap and easy to store.  She also said they work great for working out problems on the board.  You can glue a magnet on the back and they stick to the board.  She suggested that we do not need to go out and buy magnets, but instead when you get a magnet in the mail from a business that you didn't really want and are not interested in, instead of throwing it away cut it up and glue it onto your pom poms.