Mohammed and Daria are working together to solve this problem:
Now play each clip as you read the summary: how is learning taking place?
What is significant about each clip for you? What are your thoughts after listening to all the clips?
Mohammed: "Mmm, this is weird... we are not given anything in-between [the 2nd and 5th terms]."
As they flick through the book, Mohammed is surprised to find logs in the chapter on series:
Mohammed: "What is this? This log... Look, there's log..."
Mohammed then finds what he was looking for, but it appears that his method might not work for this problem.
Mohammed: "It wouldn't work, we need two values."
Daria: "But we do have two numbers, don't we?"
Mohammed: "Yes, but they're not close to each other... Wait a minute..."
Daria: "Do you want me to try a half?"
She tries a common ratio of 1/2 to see if it works (it doesn't), at which point Mohammed notices that the common ratio must also be negative, and explains why.
Mohammed: "Have you guys done part 2... it's weird..."
Daria: "Oh yeah!"
Mohammed guides Daria through the method: "It will be better to put the other one on top... the ar^4... it will cancel easier."
Mohammed: "I don't know why I didn't do that at the beginning... it's weird... I don't know why I didn't see it!"
Daria: "It's kind of interesting that we used so many different things to find... I'm pretty sure there's one, sort of, formula to find this."
Mohammed: "I really like this chapter because you can check all your answers... if it doesn't make sense, if you don't get the next term, then you're wrong."