From the Jan 2016 CC Alg I Regents

For some reason the Regents loves rational vs irrational.
Look at the 4 expressions on the TI-84.
Which one(s) result in something different?

If you said (II) you are correct.  What makes (II) different?  
It is irrational!  Do you see a pattern?  You should not see a pattern 🙂
Some popular examples of irrational numbers are: √2, √3 and  ∏.

In contrast, all other choices are rational.
What word is in the word rational?  (sometimes s’s say rat!!)
OK, um what Math word is in the word rational?  (ratio!!)
Rational means can be written as a fraction and rational numbers terminate or have a pattern.  -.025 terminates as does 5 and 21 so they are all rational.