Fill in the numbers according to the law: (8/9), (4/9), (2/9), (1/9), how many
按规律填数：(8/9)，(4/9)，(2/9)，(1/9)，多少
<gadget id="calculator">1 / 9</gadget>
<output>1/9 = around 0.111111</output>

<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">(1/9) * (1/2)</gadget>
<output>1/18 = around 0.055556</output>

<result>1/18 = around 0.055556</result>