let's say is "x".
so, "x" is the whole or 10/10 whilst 0.002 is 1/10 then, let's check
[tex]\bf \begin{array}{ccll}
amount&fraction\\
\text{\textemdash\textemdash\textemdash}&\text{\textemdash\textemdash\textemdash}\\
0.002&\frac{1}{10}\\\\
x&\frac{10}{10}
\end{array}\implies \cfrac{0.002}{x}=\cfrac{\frac{1}{10}}{\frac{10}{10}}\implies \cfrac{0.002}{x}=\cfrac{\frac{1}{10}}{1}
\\\\\\
\cfrac{0.002}{x}=\cfrac{1}{10}\implies \cfrac{0.002\cdot 10}{1}=x[/tex]