1. Calculate: $(0.12+0.36+0.5) \times(0.12+0.36)-(0.12+0.36)^{2}=$
【Answer】 0.24
Analysis:
$$
\begin{aligned}
\text { Original expression } & =(0.12+0.36) \times(0.12+0.36+0.5-0.12-0.36) \\
& =0.48 \times 0.5 \\
& =0.24
\end{aligned}
$$