Using calculated values in an action message

[Zaniwoop]

if I have a trigger that uses a calculated value, for example

({A.last} / {B.last}) < 1

and I then action a message that I hoped would give the value of ({A.last} / {B.last}).

If I use {ITEM.VALUE} in the messages, I get the value of {B.last}

How do I get the value of the calculations?