Calculation: (-2(2/3))**2=How much.
计算：(-2(2/3))**2=多少．
<gadget id="calculator">8 / 3</gadget>
<output>8/3 = around 2.666667</output>

<gadget id="calculator">-(8/3)</gadget>
<output>-8/3 = around -2.666667</output>

<gadget id="calculator">(-8/3) ** 2</gadget>
<output>64/9 = around 7.111111</output>

<result>64/9 = around 7.111111</result>