Maybe there's already a way to do this, but it seems to me that it would be useful to be able to refer to the answer on a previous line, like the Ans key on a T

Maybe there's already a way to do this, but it seems to me that it would be useful to be able to refer to the answer on a previous line, like the Ans key on a TI calculator. So: 2 + 3 (=4) Ans * 2 (=8)