interactive, allows students to communicate with each other, teach each other and get the important part of the problem solving. >> does anyone at this table know what a polynomial is? i have no idea. >> it depends on kids having that time carved out at home where there is a focus on homework, there is a value on educational team and achievement. i would be remiss if i didn't mention school choice in washington, d.c. there's the opportunity scholarship fund that is now finding 91% high school graduation rates for kids from families who only make $21,000 a year getting 91% graduation rate. that is a huge success that i think we should be seeing more on the front pages. >> what is a polynomial? sal? >> it's an expression with -- i don't want to get technical. >> come on, sal. >> there's videos on kahn academy on youtube. >> i'm going to look at a video because i'm embarrassed.