10. (8 points) A number plus 5, multiplied by 5, minus 5, and then divided by 5, the result is still 5, what is this number
【Solution】Solve: $(5 \times 5+5) \div 5-5$
$$
\begin{array}{l}
=30 \div 5-5 \\
=6-5 \\
=1
\end{array}
$$

Answer: The number is 1.
Therefore, the answer is: 1.