The ratio of the largest single digit to the smallest composite number is equal to the ratio of a certain number to (1/18). Find this number.
最大的一位数与最小的合数的比等于某数与(1/18)的比，求这个数．
<gadget id="calculator">9 / 4</gadget>
<output>9/4 = around 2.25</output>

<gadget id="calculator">1 / 18</gadget>
<output>1/18 = around 0.055556</output>

<gadget id="calculator">(9/4) * (1/18)</gadget>
<output>1/8 = around 0.125</output>

<result>1/8 = around 0.125</result>