Q: You start eating a half a pizza, then eat the remaining half of the half and continue to eat the pizza this way. Will you ever finish? Explain your reasoning. How is this a sequence?
A: In theory, no, you will never finish the pizza. By continually cutting the remaining pizza in half each time you will become closer and closer to zero each time, however, you will never reach it. This is an infinite sequence with an infinite number of terms, because we are calculating how much of the pie remains. Were we calculating how much of the pie we had eaten, this would be a geometric series.
(In theory you would never finish the pizza, however, were we to actually try this I am sure it would eventually all be devoured)