4*((1/4)-(1/9))*9.
4*((1/4)-(1/9))*9．
<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">(1/4) * 4 * 9</gadget>
<output>9</output>

<gadget id="calculator">1 / 9</gadget>
<output>1/9 = around 0.111111</output>

<gadget id="calculator">(1/9) * 4 * 9</gadget>
<output>4</output>

<gadget id="calculator">9 + 4</gadget>
<output>13</output>

<result>13</result>