Question

Classify each number as rational or irrational.

Answer 1

A number is rational if it can be expressed as the ratio between two integers (of course the denominator can't be zero).

-1/16 is already a fraction, so it's rational.

0 can be expressed as a fraction: $\frac{0}{n}$ for any non-zero integer $n$ you like

$\sqrt{2},\sqrt{3}$ can't be expressed via a fraction between integers, and thus they are irrational.