Shay teaches Tally how to ride a hoverboard, which involve special grippy shoes, magnetic crash bracelets so you don't fall, and a belly sensor. Also, for some reason, you have to keep using the word "extreme!"
The hoverboards, like the crash bracelets, use magnets to levitate, so they only work over metal.
Most of this chapter is about how Tally learns to use a hoverboard. And as the title indicates, she's not so good at first.
But we also learn that Shay only uses Tally's ugly nickname (Squint) as an insult. Which is weird, because everyone else uses ugly nicknames just like normal names.
Also, Tally and Shay are about the same age, so they should turn pretty at around the same time.
But Shay seems a little strange and quiet around the topic of being turned pretty. That's probably not a huge plot point, right?