9. The natural number 2015 can be expressed as the sum of $\qquad$ consecutive odd numbers.
【Answer】 31
【Question Type】Calculation
【Analysis】
Comment: Remember, there is no match in the world, the number of squares! It refers to the sum of consecutive odd numbers starting from 1, which equals the square of the number of odd numbers, i.e., $1+3+5+\cdots+(2 n-1)=n^{2}$.
2015 can be expressed as the sum of consecutive odd numbers, then $2015=[1+3+5+\cdots+(2 n-1)]-[1+3+5+\cdots+(2 m-1)]=n^{2}-m^{2}$, so it can be written as the sum of $n-m$ consecutive odd numbers, $2015=5 \times 13 \times 31=(n+m)(n-m)$, expressing 2015 as $2015=65 \times 31$, the maximum value of $n-m$ is 31, so it can be written as the sum of at most 31 consecutive odd numbers.