How do you express the number 0.001 as a fraction?

To express the number 0.001 as a fraction, we first identify the place value of the last digit in the decimal. The digit '1' in 0.001 is in the thousandths place. This indicates that 0.001 is equivalent to 1 out of 1000 parts.

Therefore, the fraction representation is (\frac{1}{1000}). This shows that if you divide one whole into 1000 equal parts, 0.001 represents one of those parts.

In understanding this representation, considering the other options helps reinforce the correct choice. For instance, (\frac{1}{100}) represents 0.01, which is ten times greater than 0.001. Similarly, (\frac{1}{10}) equals 0.1, and (\frac{1}{10000}) represents 0.0001, which is ten times smaller than 0.001. Both of these are not equivalent to 0.001, thus clarifying that the accurate representation is indeed (\frac{1}{1000}).