2、To make the equation $\frac{1}{2} \times\left\{\frac{1}{3} \times\left[\frac{1}{4} \times(145-1)-\square\right]+4\right\}=7$ true, the number that should be filled in the box is
【Analysis】The original expression becomes: $\frac{1}{3} \times\left[\frac{1}{4} \times 144-\square\right]+4=14$
$$
\begin{aligned}
\frac{1}{3} \times\left(\frac{1}{4} \times 144-\square\right) & =10 \\
\frac{1}{4} \times 144-\square & =30 \\
\square & =6
\end{aligned}
$$