c) 382 605 × 4;

* Hướng dẫn giải

c) $\begin{array}{l}\times \begin{array}{l}\text{ 382\hspace{0.17em}\hspace{0.17em}}605\\ 4\end{array}\\ \text{ 1530\hspace{0.17em}\hspace{0.17em}}420\end{array}$