Simple calculation: (2/9)-(7/16)*(2/9).
简便计算：(2/9)-(7/16)*(2/9)．
<gadget id="calculator">2 / 9</gadget>
<output>2/9 = around 0.222222</output>

<gadget id="calculator">7 / 16</gadget>
<output>7/16 = around 0.4375</output>

<gadget id="calculator">(7/16) * (2/9)</gadget>
<output>7/72 = around 0.097222</output>

<gadget id="calculator">(2/9) - (7/72)</gadget>
<output>1/8 = around 0.125</output>

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