well, notice first off, 0.097, has three digits after the decimal point, thus it has three decimals. What does that mean? well, "we add as many zeros to the bottom as there are decimals, and lose the dot", what the dickens? anyhow, let's do so,
[tex]\bf 0.\underline{097}\implies \cfrac{0097}{1\underline{000}}\implies \cfrac{97}{1000}[/tex]