The most recent answer provided by AutoMathic becomes the new default referent of a pronoun such as "that":
> How much is Pi over two?
(Find 3.14159/2)
1.570795 is PI OVER TWO.
Anything else?
> What's 7.5% of that?
(Find 7.5(1.570795)/100)
0.117809625 is 7.5% OF THAT.
This behavior allows calculations to be done piecemeal, building-up results bit-by-bit to see and use intermediate values:
Anything else?
> What percentage of Pi is that?
Let 'P' stand for "PERCENTAGE"
(Find P)
Solving for P:
P 3.14159
--------- = 0.117809625
100
3.14159
P ------- = 0.117809625
100
P 3.14159 = 100 (0.117809625)
P (3.14159) = 100 (0.117809625)
100 (0.117809625)
P = -----------------
3.14159
P = 3.75 (or 15 / 4, or 3 & 3 / 4)
3.75 (or 15 / 4, or 3 & 3 / 4) is THE PERCENTAGE.
Note that even though AutoMathic introduced its own noun, "PERCENTAGE", and the user referred to a pseudo-noun, "Pi", their appearance did not supersede the user's intended referent, the last result. Similarly, other "generic" nouns ("number", "amount", "fraction", "quantity", "part", "portion", "multiple", and well-known constants) do not supersede the user's specific nouns as referents of a pronoun.
Referring to the last result with a pronoun is a very simple way to pose follow-up questions. Follow-up questions in general are the topic of the next section.