What is the value of $\frac{1}{10}-\frac{1}{100}+\frac{1}{1000}-\frac{1}{10000}$?
Solution 1: Converting the fractions to decimal numbers, we have:

$$
\frac{1}{10}-\frac{1}{100}+\frac{1}{1000}-\frac{1}{10000}=0.1-0.01+0.001-0.00001=0.0909=\frac{909}{10000}
$$

Solution 2: Performing the operations, we have:

$$
\frac{1}{10}-\frac{1}{100}+\frac{1}{1000}-\frac{1}{10000}=\frac{1000-100+10-1}{10000}=\frac{909}{10000}
$$