answer: Billy teaches #Person2#, his grandpa, to use an ATM card and advises him to memorize his PIN instead of writing it down. #Person2# thinks the machines aren't very difficult to use.
documents: #Person1#: How do you use an ATM card, Billy?
  #Person2#: It's easy, grandpa. Insert you card into the machine here. Then wait a moment. OK. Now you enter your PIN. It should have four numbers.
  #Person1#: Oh yes. I'Ve got it written down here. Just a minute.
  #Person2#: You really shouldn't write it down. You should memorise it. You can change it to a more convenient number if you like.
  #Person1#: OK, I'Ve entered my PIN. There are several options on the screen. I guess I just choose which service I want, don't I?
  #Person2#: Yes. Choose the service you need to use. If you choose to withdraw money, the machine will ask you how much you want.
  #Person1#: I can just enter the amount using the key, right?
  #Person2#: That's right. Give the machine a moment to process you request. Then take your money.
  #Person1#: These machines aren't very difficult to use. In fact, I quite like them. They are much faster than dealing with a band clerk.