6. (5 points) A number, when reduced by 5 times, and then increased by 20 times, becomes 40. This number is $\qquad$
【Solution】Solution: $40 \div 20 \times 5$
$$
\begin{array}{l}
=2 \times 5 \\
=10
\end{array}
$$

Therefore, the answer is: 10.