variable roles

1. Fixed value make for great solid ratios.  causing them to be the backbone of most programs.

2.      square

      x = -1;
      y = -1;
      cin >> x;
      y = x*x;
      cout << y << endl;

3. a. the score in a game
        interest on a loan/investment
    b. the score in a game is constantly adding your new progress to the value.

4. accumulator adds stuff into one value, aggregator takes all the values and puts them into a list.
http://scratch.mit.edu/projects/26877188/
http://scratch.mit.edu/projects/26877764/