mike will roll two number cubes labeled 1 through 6. after each roll, he adds the two numbers showing and records the results. He will roll the cubes 500 times. About how many times can he expect a sum greater than 8?
+2354 Haha number cube. I like that term.
Have a look at this table;
As you can see there are 10 out of 36 possibilities greater than 8.
Therefore the chance is 10/36 = 0.2777777 = 27.77%
Reinout 
+118723 I'll just finish it.
In 500 rolls he can expect to get this oucome about 27.77...%* 500 = 139 times.
$${\mathtt{0.277\: \!777\: \!777\: \!77}}{\mathtt{\,\times\,}}{\mathtt{500}} = {\frac{{\mathtt{1\,250}}}{{\mathtt{9}}}} = {\mathtt{138.888\: \!888\: \!885}}$$
