7. Set
$$
A=\left\{x \left\lvert\, x=\left[\frac{5 k}{6}\right]\right., k \in \mathbf{Z}, 100 \leqslant k \leqslant 999\right\},
$$

where $[x]$ denotes the greatest integer not exceeding the real number $x$. Then the number of elements in set $A$ is $\qquad$