Actually, there are infinitely many rational numbers between them, but let's take the one "in the middle".
so the number between 1 and 2 is 1.5
so the number between them would be
\(-\frac{1.5}{6}\)
but since this is not a proper way of writing it, we should multiply both sides by something to get rid of the Point, let's say we multiply it by 2.
\(-\frac{3}{12}\)
and this is an example of a rational number between-1/6 and -2/6