chapter 7 video.
click here to watch the chapter 8 video.
click here to watch the chapter 9 video.
click here to watch the chapter 10 video.
chapter 11: how much is a trillion?
click here to watch the chapter 11 video.
click here to watch the chapter 12 video.
click here to watch the chapter 13 video.
click here to watch the chapter 14 video.
click here to watch the chapter 15 video.
click here to watch the chapter 16 video.
click here to watch the chapter 17a video.
click here to watch the chapter 17b video.
click here to watch the chapter 17c video.
click here to watch the chapter 18 video.
click here to watch the chapter 19 video.
click here to watch 