3. Calculate using a simple method (the process must be written)
(1) $25 \times 26 \times 8$
(2) $340 \times 40 \div 17$
(3) $440 \times 15 + 480 \times 15 + 79 \times 15 + 15$.
【Solution】Solution: (1) $25 \times 26 \times 8$
$$
\begin{array}{l}
=25 \times 8 \times 26 \\
=200 \times 26 \\
=5200
\end{array}
$$
(2) $340 \times 40 \div 17$
$$
\begin{array}{l}
=340 \div 17 \times 40 \\
=20 \times 40 \\
=800
\end{array}
$$
(3) $440 \times 15+480 \times 15+79 \times 15+15$
$$
\begin{array}{l}
=(440+480+79+1) \times 15 \\
=1000 \times 15 \\
=15000
\end{array}
$$