When a=3, b=0.3, c=0.6, then a**2-c/b=how many.
当a=3，b=0.3，c=0.6时，则a**2-c/b=多少．
<gadget id="calculator">3 ** 2</gadget>
<output>9</output>

<gadget id="calculator">0.6 / 0.3</gadget>
<output>2</output>

<gadget id="calculator">9 - 2</gadget>
<output>7</output>

<result>7</result>