I thought this would be easy, but it's eluded me!

If I have a column of data, how do I extract the last entry in that column? I want this to be a variable so that as I add entries, it gets updated - i.e., to make a running list.

For example - if my data looks like this:

A1 is 5
A2 is 12
A3 is 30

Then I want B1 to show 30. However, if I add an entry A4=55, then B1 should change to be 55.

It's weird because I can easily set B1 to be the MIN of my range, say A1 to A50. I can set B1 to be the MAX or AVG of this range. But I can't find a function to show the last entry in the list.