Results: So-so. Because of the fractions exercise, Benny immediately pointed to the 100% bar and said "I want that cookie!" Afterwards, he was able to point out which is which percent, but only by reading the labels underneath the picture.
Exercise 2: Benny likes the Angry Birds app (too much). When the Angry Birds app is loading, it shows a percent complete. So I point that out to him and ask him what percent. A certain version of Angry Birds also has levels that score on a percent.
Results: Mediocre. He understands that when the loading bar gets to 100, the app starts. He also looked at the percentages and seemed to be thinking, but his focus kept returning quickly to the game and it was hard to tell if he got the concept.